Focus is a buff that used only by The Defect that increases the passive and evoke effect by 1 of the channeled orbs (except the plasma orb).
You can get focus by casting the powers defragment (1 or 2 if upgraded) or biased cognition (3 or 4 if upgraded).
biased cognition also causes a focus loss per turn, just like wraith form’s dexterity los per turn