Zarayna, the Emberqueen

Wither, Hexproof
When Zarayana, the Emberqueen enters the battlefield, put X -1/-1 counters on up to X number
of creatures an opponent controls, where X is the number of elementals you control.

Other elementals you control have {1}{b}{r}: Regenerate this creature

Whenever you cast an instant or sorcery spell, proliferate.