Tia & Tina, Twin Assassins

Ninjutsu {1}{u/b}({1}{u/b}, Return an unblocked
attacker you control to hand: Put this card onto the
battlefield from your hand tapped and attacking.)
Whenever this creature attacks or enters the battlefield attacking, Create a copy of Tia & Tina,
Twin Assassins tapped and attacking. This copy
is not legendary, cannot be copied, and is
sacrificed at the beginning of end phase.