Anti-Combo is a feature in Velocity that basically decreases the amount of knockback you take relative to how many hits in a row your opponent has gotten on you. You know how in fights, normally when you get hit into a combo the combo more or less feeds off itself as you're knocked back further and further? The anti-combo option basically detects when you start getting combo'd, ramps up your velocity so you can get out of the combo quicker, then pushes your velocity back down to it's normal values afterwards.