A couple of people have asked me about Brawler builds or asked how my plasma beam always seems to find them. I don't often see him played, at least not in pubs and he's practically the only hero I play anymore so I figured I'd share a few tips.
Foundations first. Dustin Brawler is an int-based support hero. He's got a decent set of skills available with auto-targeting rockets, a line aoe skillshot, a placable aoeot that also debuffs spell resist, and his ult lets him reset his cooldowns. On the surface, he's a fairly average hero. But the most important thing is how well his skills synergize with each other. He does have his shortcomings, however. He isn't very robust and has no significant escape mechanisms of his own. So positioning is important as well as mobility. Understanding the range of your skills and how far away you can hit targets, as well as hit-and-run and fire-and-forget strategies are key. So lets get into some details.
HP: Dustin's probe hovers overhead and follows a short distance behind when he's in motion. It gives you a passive radar scan that lets you see location of both invisible enemies, as well as those out of sight. It doesn't, however, make invisible enemies directly targetable. But that's OK for Dustin because none of his skills need to directly target. His rockets home in on targets, prioritizing heroes and his beam and pulse are AoE so they will hit anything within their effect zone. The radar also gives advance warning against ganks as you can see people coming even if they are behind LoS blockers. You can also see pesky burrowing Unix creeping about as well as Crackling's burrowed zerglings.
Plasma Beam (Q): The plasma beam is a line AoE that partially ignores the targets' spell resist. This gives you a very handy way to deal damage to early-game SR stackers. But it's also a skill shot and a hard one to nail at that. The point to remember is that the beam comes not from the mech unit, but from the drone. This involves the drone slowly flying into position, and the beam tracing a path from it to the target point. Additionally, the target point must be in range of Dustin, even though the beam doesn't come directly from him. This sets up a kind of triangle requirement where both Dustin and the drone need to be within range of the target point before the beam fires. But that's OK because there's a trick to this which I'll get to later. But, at the end of the day, Plasma Beam should be the bread-and-butter of any decent Dustin player. I get the first rank at level 3, then focus on it as top priority to get maxed.
Rockets (W): These are auto-targeting dumbfire rockets. You hit W and launch rockets at up to four different targets with priority on enemy heroes. These are very handy early on as they will auto-target and, barring fancy blink tactics, they will reliably hit, whereas the plasma beam can miss, costing you valuable early-game energy. I get one rank at level 2, then it is the second priority skill when I can't put a rank into Plasma Beam.
Auto Pulse (E): Often overlooked and underestimated, I wish I had a dime for every time an enemy just stood blithely under my drone pulses taking damage and stacking on the spell vulnerability only to be nailed by a double laser/rocket/reset combo. Even more entertaining is when they try to run away with low life right through the AoE, only to be killed by the pulse. But this skill has another, much more important use. It gets the drone into a desired position quickly. It follows in spurts when you're moving and it floats lazily into position when you fire your plasma beam, but it zips to the destination super-fast when you use your E skill. I often use this to send the drone to watch a blind spot when attacking a tower to give early-notice of an incoming gank. I also use it to zip the drone quickly to a spot and then fire a plasma beam from an oblique angle. People often expect Dusting's laser to come at them head-on. But I often send out the drone first and attack from diagonals, sideways, even from behind them. I also send the drone in over a tower to fire a laser far deeper into their territory than they expect, often catching them by surprise when they think they're safe and teleporting home. It's also a very good early-game damage-dealer for lane creeps and deals easily underestimated damage and debuffs. But the tactical utility of E is, by leaps and bounds, more important to good Dustin play. I get the first rank at level 1, but then don't focus any more until level 12.
Cooldown Reset ®: Dustin's ultimate ability lets him reset all his cooldowns. It takes a second or two (depending on rank) to activate and it takes energy so you need both a safe moment in which to use it, as well as enough energy to spare afterwords to make it worthwhile. Early-game, you're often lacking both of these so I don't even bother getting the first rank of this skill until level 10. This sets me up to immediately bump it up to rank 2 at level 11. It also means I can get my laser and rockets up earlier than opponents might suspect. But, once you get your energy sustain on point, usually by or near level 11, you'll be able to spam rockets and lasers, often doubling up on them for incredible burst damage.
Some people try to play Dustin as a burst caster which, admittedly, he can pull off. But I've always been more comfortable leveraging his ability to constantly be laying down damage through strategic cooldown cycling and boosting his energy sustain. The goal is to constantly pester the opposing heroes; never give them any breathing room and make sure they never feel safe even far behind their tower. And if they ever do feel safe, make them regret it. You'll need pretty robust energy management for this and, also, a pretty good income. But mainly, you want to use your E to lay down damage on enemy creeps and punish melee heroes that want to kill creeps. Once you get rockets, you can fire them off periodically when it's worthwhile. Try to make sure both your opposing heroes are within range; it's a decent range, but never as much as you'd like it to be.
Early on, you'll also be drinking energy pots like an addict. Eventually, you'll get yourself an Ihan and Space Battery>Cerebro and also a Symphonic. These will ensure you have massive sustain to just sit there and keep dishing out damage. But, most importantly, you must work with your lane partner. A Dustin can't do very much on his own, but he's awesome at setting up opposing heroes to be finished off by teammates. Sometimes I end up with a lot of kills, other times I don't, but I consistently have highest or second highest assists in any given game.
And, as said before, you've got to be aware of your surroundings and keep moving. A flat-footed Brawler is a dead Brawler. You need to be able to fire off your rockets or laser without missing a step, alert people to incoming ganks you see on your radar, step forward to fire off lasers and rockets deep into opposing territory and then just as quickly fall back so you don't get pulled or stunned. And all without any blinks to help you. Most importantly, you've got to predict what the opponent will do before you're directly aware of it. Always think to yourself, "Would this be a good time to gank me if I were them?" I've sometimes been accused of using map hacks when I intuitively predicted someone coming from around a corner and hit them with a laser/rocket combo.
Also, learn when it's better to run away, and when running away would be futile. If you're going to die anyway, refocus your attempts to taking one of them down with you or at least softening them up. Your drone will continue to damage and amp spell damage after you're dead and your laser will still fire even if the drone is moving into position when you die. Rockets in the air will also still hit their targets after you die. Post-mortem triple kills are amazing, especially when your lowly, underestimated drone gets the last hit in.
Talents: This is a bit more subjective based on your personal playstyle, but there are a few fixed points. First off, keep restoration. The sustain it offers is far more useful than any other active from the talent system. Second, get Spell Damage from the Offense tree. Lastly, pick up Health and Zeal from the Defense tree. Health is a no-brainer but Zeal is a personal favorite of mine. Since Dustin's playstyle is about constantly poking enemies, it helps to be rewarded for those pokes by a little extra sustain. Beyond that, focus on whatever talents best fit your playstyle, though I'd personally recommend energy regen and move speed from Utility, Armor from Defense, and Attack Speed from Offense.
Items: I usually start the game with Lost Treasure, 1 health pot, and 2 energy pots. Lost Treasure ensures that, even when I can't last-hit, I'm earning a constant income and also helps my sustain, to boot. My second item (other than replenishing energy pots) is Moebius Coil. This is a very important one as it actively rewards you for punishing enemy heroes. As long as you pace them out, your rockets and drone denial pulse are actively earning you cash money which fuels your energy pot addiction. Eventually, this will build into Perpetual Engine and, in turn, Symphonic Seed. Then, I round it out with Miners Goggles, also a component of Symphonic.
Now, I'm ready to start working on my Ihan Crystal. Ihan is awesome as it bulks up your Int as you carry it and later, even after you sell it for a better Int item, you'll keep the Int stacks it generated. It also is an extreme boon to sustain as you can keep yourself healed and energized to stay in-lane and keep dishing out punishment. Start with the Power Stone, then build immediately into Ihan. Once you get that done, your next step is to get a Space Battery to break the money sink that is energy pots. This will eventually build into a Cerebro, but that's a little bit later. After the Battery, I typically build my Coil into a Perpetual for increase poke reward and Int bonus, then go back to completing my Cerebro. Cerebro is important because it gives you an energy recharge all at once. Battery is 200 energy over 10 seconds, every 70 seconds so your maximum energy regen long-term is about 2.86 energy/sec. But Cerebro is 400 energy at once, every 60 seconds, about 6.67 energy/sec long-term, over twice the long-term sustain, not even counting the difference in stats provided by Cerebro. Additionally, the chain lightning and attack speed on Cerebro drastically helps your AA. You'll still be solidly a support hero, but you'll more readily be able to supplement your skills with AA. But that's just icing on the cake. The real benefit of Cerebro is the energy restore active which is not only a boon for Dustin, but also helps with team support when a teammate is low on energy.
At this point, you're likely knee-deep in mid-game. Your next goal should be to grab an Emerald Lotus to eventually turn into a Nitrogen Retrofit, then finish off your Symphonic. Symphonic will give passive energy regen that gets better the lower energy you are. This is critical to keep dishing out the pain with few pauses (if any). Once I get this far, I'll often finding myself with 3-5k minerals on hand before I know it because I never need to go back to the pool for a recharge. After Symphonic, I go for Nitrogen next. This provides a bit more utility as I can slow down enemies when I poke them to make it easier for my DPS teammates to run them down. Also, it's more Int and HP and I can never get enough of either of those. Next comes the Argus Crystal. A lot of people ask why I don't go for Argus earlier in the match as it's a pretty key item for Int characters, especially burst casters. But, as I said before, Dustin is far better as a long-term sustain caster rather than a burst caster. I'm not focused on landing the killing blow, I'm focused on whittling them down with constant punishment and setting them up for DPS on my team. So it's more important that I go for survivability items and energy regen over raw damage.
The last consistent item I go for is Silver Soul. This is a bit of an odd-ball and I've caused a few raised eyebrows at "Dustin with a Silver Soul!?!? LOL" But that speed boost has gotten me out of several sticky situations and really compensates for Dustin's lack of innate mobility enhancements like blink or speed boost skills. Additionally, it builds off Lost Treasure which I'd be getting anyway and I've always found it more worthwhile to build income generating items into something rather than just sell them. It also gives me a pretty hefty Hp and energy regen and both kinds of armor which helps counter squishiness. Lastly, whereas an item like Yamato or Warp Shard gives personal mobility and benefits, Silver Soul will help my whole team. I can hit it when we're chasing an enemy to let my team easily catch up with them (compounding the slowdown from my Nitrogen). It adds a not insignificant level of team utility to Dustin to capitalize on the fact that he's relying on his team to finish off the enemies he softens up anyway. Now, those are the fixed items that I get.
My last item is often based on what the team needs. If the enemy has a lot of healing or ridiculous spell damage, I might go for a Kura's. If they have a lot of high-HP heroes, I might go for Ancient Rune. I typically don't bother with Yamato since I don't like a lot of active items on Dustin since my fingers are already dancing handling all his skills so I prefer to stick to two active items, Cerebro and either Ihan or SS. Lastly, if they have a lot of spell resist or we generally just don't need anything else, I'll just grab a Gravity Edge. Of course, this is all presuming the game even lasts that long.
All in all, Dustin is a fairly straight-forward character as long as you remember that he has a high burden of strategic awareness and he's extremely reliant on his team to make any useful progress. You can't treat him as a one-hit wonder like Cyprus or a mobile speed-freak like Virgil. He's a highly sustainable spell damage poker if you build him right and is very good at setting up situations for his team to capitalize upon. What he lacks in burst damage, he makes up for in skill cycling. The key points are to use oblique shots from your laser to confuse opponents, punish them frequently with drone pulse and rockets, delay your ult until level 10 and 11, focus on energy sustain and passive income first, raw damage second, and be a team player.