Age Of Revelry

Age Of Revelry enters the battlefield with an era
counter for each player. When the last era
counter is removed from it, sacrifice it.
{3}: Remove an era counter from Age Of Revelry.
Any player may activate this ability.
During each player's turn, for each permanent
type, that player gains 2 life the first time a
permanent of that type enters the battlefield
under their control that turn.