The only way to get is by cheating with codes, it can't be found in the game

First rpg?

i would say don't bother the crit%/dmg is not worth speccing into INT unless you want to use quickhacks and deamons you get more boni from COOL and the Cold Blood tree especially (Dmg / attackspeed / resistance / death defy / movement speed) the ninjutsu tree isn't bad either for dmg if you can manage to stay undetected long enough

really it should be a reflex implant, like heal-on-kill.