Thunder Lance X Tempest Buster! (X-BT01/0028EN) (X-BT01)

You may only cast this card if your opponent's life is 5 or less, your cards have attacked three times or more during this turn, and neither you nor your opponent has a monster in the center. (Link attacks count as one attack!)
[Cast Cost] [Pay 3 gauge]
Deal 5 damage to your opponent! This card cannot be nullified and the damage cannot be reduced. If your opponent's life would become 0 by this card, it cannot be changed by your opponent's cards. (Unrevivable)