Hellborn Wyvern

Flying
{x}{b}{r}: Hellborn Wyvern gets +X/+0 until end of turn, then incarnation X (Each player may put a permanent card with converted mana cost X or less onto the battlefield.)
Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)