Frayla, Servant of Demon Fire (ABC-RD-030 SR) [Arcana Battle Colosseum]

When this card enters the field -> It gains [Swiftness] until end of turn if you don't control another resonator. Whenever this card attacks -> Another target resonator you control may gain [+400/0] and [Swiftness] until end of turn. If it does, at the next end of turn -> Its controller banishes it.