Tilonalli's Summoner (RIX-121) - Rivals of Ixalan

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
Whenever Tilonalli's Summoner attacks, you may pay . If you do, create X 1/1 red Elemental creature tokens that are tapped and attacking. At the beginning of the next end step, exile those tokens unless you have the city's blessing.