Etali, Primal Mayhem

Trample, Ward {4}
Whenever Etali attacks, exile the top card of each players library. Each opponent may cast any
spells they own from among those cards by
paying life equal to the spells mana value rather
than paying it's mana cost, and if they cast a spell
this way, they can't target you or permanents you control. Then you may cast any spells exiled this
way without paying their mana costs.