Mirrorweave

Undaunted (This spell costs 1 less to cast for each opponent.) Destroy all creatures.

Flying, first strike If a source would deal damage to an opponent or a permanent an opponent controls, that source deals double that damage to that player or permanent instead. If a source would deal damage to you or a permanent you control, prevent half that damage, rounded up.

Haste Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)