Looks like it's hard to build unarmed build as they get bonus damage for str and ap reduction for dex, so probably best build would be 10str/10dex/agi 8/con 3/per 3/will 3/int 3...unarmed glass cannon for lyef!
Wrong.
Unarmed is sick overpowered. 3 str/10 dex/8agi/3 con/3per/7 will/6int (for crafting) - pump first two stat points into dex, next into int to get crafting perks, and then from 16 on into agi or more dex (for crit and melee skill bonus - I'm deciding this tradeoff right now).
It's all about stacking feats and the skills force emission and telekinetic proxy. Nimble + Reckless + Opportunist + expose weakness + critical strikes + combo + vile weaponry + taste for blood + expertise + fancy footwork. Then, after that you can decide on what else to take (probably power management + skinner?), but the way that thing layers on damage...
It's fucking insane. You miss out on the damage bonus from str, but especially with bladed fists (which you should be using to take advantage of taste for blood + vile weaponry), you are going to be dropping anyone in no time. The only headache is heavily armored enemies (robots and bladelings and whatnot), but that's what expose weakness is for.
I don't know if this is the most powerful build in the game, but it's on the short list with heavy AR/sniper based on what I've tried out.