Auroxis

Endurance is tight, but I went through enough iterations to get it stable with Musc and without Ageless. Requires steady casting of Toroidal Bubble but that's not too big of a deal.

I went Mace on mine for the Achilles' procced Poisonous Ray (to get more DPS out of shifting tides procs) and FFB procced Disruptor Beam, but looking back I'd go Earth instead. Fissure applies its damage faster, and provides a more steady source of FFB procs for a very strong AoE chain alongside Whitecap. And Seismic is a great boost for your personal DPS. The only downside is Rock Armor FX.

@aethereal I tested with damage procs:

So from my tests the Teleport+Attack "Redirect" powers proc in a quirky way. The PPM calculation seems to be using the origin power's recharge and area factor (which is none) rather than the executed power's recharge+area factor, making Spring Attack and a few other similar powers have a 90% proc rate. I'd love others to test it themselves to see if they get similar results.

I get it @Maelwys, but i also linked to a showcase of the build clearing a +4x8 mission with vengeance mobs and an EB with defensive clickies to spare, so it's not like i didn't take tanking into consideration.

I wouldn't go Mace Mastery with Robots/Time, as Protector Bot's shield makes the the +def from Power Boost Farsight superfluous for the most part and Scorpion Shield is overcapping you by quite a bit. You can just go Mu Mastery for the res shield, and +rech and -res procced Thunder Strike instead (so you have all 3 -res procs covered, and force feedback proc makes it easier to build recharge). You can IMO even drop the fighting pool for an easier time with endurance, since you're already softcapped. It's definitely not a losing battle to go heavier with your proc slotting, just requires a bit of tinkering.

Not only does the MM have time to fire off those procced AoE's, but you get to fire the opening volley to thin the herd which makes your pet attacks more focused and efficient. That's why I enjoy playing with procced attacks on MM. Also, you don't necessarily have to proc those fast recharging ones in the primary powerset. In the secondary powerset and power pools there are often excellent proc opportunities (like Whitecap, Explosive Blast, Thunder Strike and more) which not only contribute damage but also inflict -res and grant +rech via procs. Yes you need to find a balance with endurance issues and defensive concerns, but that's part of the building process. Take the build I posted for example. You cast tide pool and command your minions into it, then Whitecap into the pack, fire off the -regen grenade, and then Explosive Blast (which in hindsight should be slotted with KB->KD). Through this you get very high FFB uptime, two -res procs on the pack, and enough damage to kill minions so your pets can focus on the remaining debuffed LT's and bosses.

Here's a build for you to work with. Has positional defenses close to the softcap (protector bots give +19.5%), S/L near hardcap, and some nice FFB and -res procced attacks to keep your PotD perma and DPS high. Mastermind (Robotics - Marine).mbd

Force Field is generally overlooked since it's seen as a vanilla powerset and pairing, but after the buffs to the powerset and certain MM epic power picks it's become quite a strong pairing with bots. You can softcap yourself with bots fairly easily, you have some -res, a proc bomb, and you get CC protection which frees up a Destiny slot for either Rebirth or Ageless. The softcap and CC protection means you can be fairly aggressive with your attacks, as combining your procced-out Force Bomb with more aggressive power picks (like Fold Space and Mu Mastery's Thunder Strike+Electrifying Fences) turns you into less of a stereotypical boring AFK mastermind and more of a sentinel with powerful pets, which shores up the DPS issue with bots. Bots also gives you -regen which FF lacks.

As far as AoE goes, Dark doesn't pair amazingly well with Marine due it putting you in Melee range which isn't great for tight cones like Tenebrous Tentacles and Nightfall. However you still have Blackstar which puts you there, and if you bunch mobs up you can still get some mileage out of a procced Torrent. You can pick up Dark Mastery here for a thematic fit and a way to get more burst AoE with Gauss procced Spirit Drain (Oppressive Gloom should stack with Dark Pit, but I never tested how viable that is). For debuffing, Dark's -ToHit pairs nicely with Marine as you don't have that much +Def on it outside of Barrier Reef. So it shores up that defensive layer nicely. For DPS, Dark is fine with Moonbeam and procced Gloom+Torrent, but isn't anything special outside of that. Marine helps on that front as procced Whitecap + Shifting Tides covers your DPS in teams. Picking up Fire Mastery for procced Char+GFS will help further with DPS, but may be a stretch thematically. Consider getting procced Weaken Resolve to get some more -res for your team in your rotation.

Just keep in mind that even on 4-star content people don't lean into building towards def/res caps because of Barrier.

You can see my Bio/Battle Axe build in action here, it's DPS focused but has well enough defenses for most content. Bio gets a lot of its tankiness from uptime on its self buffs:

On Controller I use 5-piece Ragnarok + Gauss Proc On MM it depends, but generally same as above (Thugs like using the gauss proc in Enforcers) On Corruptor I use 3-piece ATO (end/heal proc), Purple Damage Enhancement (semi frankenslot to maximize damage), and Gauss Proc can go here or in Aim depending on preference (I prefer to skip Aim on my Fire/Marine because between Pool+Whitecap+Inferno cast time I spend enough time setting up a nuke). On Defender i've yet to decide, slotting ATO's in it is good for passive heal/absorb but isn't quite as impactful as the +end corr has, and Gauss Proc consideration is similar to corr (On my Marine/DP I placed it into Dark Epic's Spirit Drain for my Hail of Bullets opener).

To be clear, I slot mine for %damage Enhancement, NOT damage procs. And as I stated, I HAVE tested damage procs, and they work as I stated: Minimal chance of activation, every 10 seconds, just like how damage auras operate. If the damage aura comparison doesn't work for you, think of it like a Rain power ala Rain of Fire and Ice Storm. Except instead of dealing a little bit of damage every fraction of a second, it can deal a moderate amount of damage every fraction of a second, only when triggered by something attacking the target.

Outside of %Damage and Endurance Reduction (I prefer going for set bonuses over frankenslotting here), you can also fit the Gauss Build-Up proc into it since it has a very high chance of giving you the buff every 10 seconds, more-so in teams much like Tactics. On MM it's very similar, but on Defenders and Corruptors it gets interesting as they can slot their team heal/buff ATO's in there to trigger often. Corruptor basically gains another team endurance recovery power with some periodic healing with just 1 slot, and Defender can choose to grant the team more passive AoE healing and Absorb with two ATO placements.