Jiassa, Magus of Multitudes

Clone {u}{b} (As you cast this spell, you may pay
an additional {u}{b}. If you do, when this creature
enters the battlefield, create a token that is a copy of it,
it gains haste. Exile it at the beginning of the next
end step.)
Creature tokens you control aren't legendary.
At the beginning of your upkeep, create a token
that is a copy of another target creature you
control.