Fleshborn Muse

At the beginning of each player's upkeep, that
player discards a non-Spirit creature or planeswalker card. If they don't, they lose life
equal to Fleshborn Muse's power.
{3}, Discard a non-Spirit creature or planeswalker
card: Fleshborn Muse gets +X/+0 until end of
turn, where X is discarded card's mana value.