So the first few times I went through ME3 I didn't really look at the combo system. It was only in the last year when I replayed my Sentinel and Vanguard that I went deep into it. What Infiltrator and Soldier builds/squad comp would you guys recommend for SP Insanity? I know the game's easy so it doesn't require specific shit but I like min-maxing.
For best combo use on Soldier you need to spec into Concussive Shot since once you unlock the Amplification node you can perform all the three Tech combos like the Engineer. You also need to spec AR into Power use so that you can throw off a CS to detonate a combo whilst you're still in the middle of an Adrenaline Rush. The build for Soldier which I use is
Adrenaline Rush: Damage / Duration / Power Use
Concussive Shot: Radius / Recharge Speed / Amplification
Frag Grenade: Damage / Max Grenades / Shield Overload
Cryo Ammo: Squad Bonus
Disruptor Ammo: Damage / Headshots / Damage
Incendiary Ammo: Damage / Headshots / Explosive Burst
Combat Mastery: Damage / Headshots / Weapon Master
Fitness: Durability / Shield Recharge / Fitness Expert
Inferno Grenade (Bonus Power): Radius / Max Grenades / Radius and Shrapnel
I take another grenade as a bonus power because the extra grenades nodes you can unlock in both of them stack, so you can have 9 grenades at your disposal. Frag Grenades aren't really used unless I'm up against an Atlas or something, most of them time I just spam Inferno Grenades to set up easy group fire explosions since they're a primer.
If you feel like you won't use Frag Grenades much and that you can afford to lose 2 extra grenades since you'll also use Ashley(she's one of the best squadmates for Soldier, I'll explain why soon) for more Inferno Grenade madness, then you can just spec it up to the 4th node and then spec the 5th and 6th nodes of Cryo Ammo for your squad instead, for something like:
Frag Grenade: Max Damage
Cryo Ammo: Squad Bonus / Headshots / Freeze Chance
Normal build for Infiltrators is
Tactical Cloak: Damage / Recharge Speed / Sniper Damage
Cryo Ammo: Squad Bonus / Headshots / Freeze Chance
Disruptor Ammo: Damage / Headshots / Damage
Sticky Grenade: Damage
Incinerate: Damage / Recharge Speed / Armor Damage
Sabotage: Duration / Recharge Speed / Tech Vulnerability(this power is fucking awesome btw)
Fitness: Durability / Shield Recharge / Durability
Operational Mastery: Weapon Damage / Weight Capacity / Sniper Damage
Energy Drain (Bonus Power): Radius / Drain / Damage
If you want to join the ranks of the Yolo squad and use Shotguns/Talon with your infiltrator, then just swap the sniper rifle options for the opposing nodes.
Now for squadmates, due to how powerful tech combos are the best squadmates are those who can both prime and detonate them(for both the Soldier and Infiltrator since both classes rely on them), and the squaddies who can do that are Ashley, James, Garrus, EDI and Kaidan. Some bring more to the table though, and those are Ashley, James and Garrus. Lets start with Ashley.
Ashley has two primers, Disruptor Ammo and Inferno Grenades, which set up Tech Bursts and Fire Explosions respectively. She also has Concussive Shot, which means that not only can she detonate her own tech combos, due to her Inferno Grenades and Disruptor Ammo not being on a cooldown, but can also detonate Shepards and other squadmates. Not to mention that due to her being an offensive focused Soldier, she also gets those ridiculous weapon damage bonuses, making her an S class squaddie for a Soldier or Infiltrator Shepard to use.
James has two primers, Carnage and Incendiary Ammo, which both set up Fire Explosions. He can also detonate his own Fire Explosions, as well as detonate the tech combos of other teammates with the use of his Frag Grenades since they're not on cooldown, so just have him throw them at an opponent that's primed and watch the fireworks. The dude is also a fucking tank, and rarely dies, he'll 1v1 a damn Maruader in a melee battle and come out on top ffs.
Garrus is next, and he has one primer in the form of Overload, which can set up Tech Bursts, but unlike the other two unfortunately he cannot detonate his own combos, since his detonators share a cooldown with his Overload(the downside of not having a grenade power). He can still detonate other squadmates combos though, with the use of Overload, Concussive Shot and that phenomenal Proximity Mine.
The reason he's here listed with Ashley and James and Kaidan and EDI aren't, is because whilst they can fill in the same role as squaddies who can set up combos but can't detonate their own, he has multiple ways to do it and also comes with the added benefit of increased weapon damage due to being an offensive focused Soldier like Ashley, along with having Proximity Mine, which brings him out of top against EDI and Kaidan.
You may notice a name missing, Tali. I didn't forget about her, she's Tech after all, but her effectiveness is so far below the rest of squaddies I named above that she wasn't worth mentioning. If you really want to use though then spec her for Energy Drain, her passive and nothing else. The drones are not worth it.
To rank the squadmates
1. Ash
2. James/Garrus(If you pick Ash then it honestly doesn't matter which one you take)
3. EDI
4. Kaidan
5. Tali
6. Liara/Javik
EDIT: Just realised that I forgot squad builds
Ashley
Inferno Grenade: Radius / Max Grenades / Radius and Shrapnel
Disruptor Ammo: Damage or Squad(depends on you) / Headshots / Damage
Concussive Shot: Radius / Recharge Speed / Amplification
Alliance Officer: Weapon Damage / Power Damage / Assault Rifles
James
Fortification: Durability / Recharge Speed / Durability
Frag Grenade: Damage / Max Grenades / Shield Overload or Armor Piercing
Incendiary Ammo: Damage or Squad Bonus(depends on you) / Damage / Explosive Burst
Arms Master: Durability / Shield Recharge / Fortification
Garrus
Concussive Shot: Radius / Recharge Speed / Amplification
Overload: Chain Overload / Recharge Speed / Chain Overload
Proximity Mine: Radius / Damage Taken / Recharge Speed (always spam this when you can against tough enemies)
Turian Rebel: Weapon Damage / Power Damage or Assault Rifles / Sniper Rifles
EDI
Incinerate: Damage / Recharge Speed / Armor Damage
Overload: Damage / Recharge Speed / Shield Damage
Unshackled AI: Power Damage / Tech Damage / Squad Bonus
That's all she needs
Kaidan
Overload: Damage / Recharge Speed / Shield Damage
Cryo Blast: Radius / Cryo Explosion / Recharge Speed
Alliance Officer: Durability / Tech Damage / Squad Bonus (The Power damage version, no idea why they named the two nodes the exact same fucking thing)
He has no need for Biotics when playing with Soldier or Infiltrator
Also, some people might ask why I don't suggest a more balanced team with a mixture of combat, tech and biotics, and the answer is simply that despite Bioware trying to push that idea throughout the series, it's never been needed, hell, it's actually proven itself detrimental, especially in ME3, since biotic and tech powers don't mix as well as Combat and Tech powers do a lot of the time.
Tech powers have priority over biotic powers, so if you cast an Incinerate and Warp on a target, and then cast a Throw in hopes of detonating a Biotic explosion, you'll actually get a Fire explosion instead, but it doesn't work the same in the opposite direction, tech powers can't detonate biotic explosions. This is why MP has become so heavily skewed towards tech, the way the combo system works means that it's more efficient to run full teams of tech users than a mixed group, and since tech powers are much more diverse than biotic powers, thats what people use.