Hoarder's Overflow

Legal in Standard, Pioneer, Modern, Legacy, Vintage, Commander

When this enchantment enters and whenever you expend 4, put a stash counter on it. (You expend 4 as you spend your fourth total mana to cast spells during a turn.)
{1}{R}, Sacrifice this enchantment: Discard your hand, then draw cards equal to the number of stash counters on this enchantment.