Star-vader, Infinite Zero Dragon

(This ability is active if you have four or more damage):When a Link Joker rides this unit, choose a rear-guard from your opponent's front row and back row, lock them, and choose your vanguard, and that unit gets +10000 until end of turn. (The locked card is turned face down, and cannot do anything. It turns face up at end of the owner's turn.) :When this unit attacks a vanguard, this unit gets +2000 until end of that battle. /:Lord (If you have a unit without a same clan as this unit, this unit cannot attack)