Moshala of Land and Sea

Other Merfolk you control get +1/+1.
Whenever a creature you control deals combat damage to a player or planeswalker, you may tap or untap target permanent.
{t} You may play target land card from your graveyard or cast target instant or sorcery with converted mana cost X or less from your graveyard, where X is the number of Merfolk you control that dealt damage to a player or planeswalker this turn. Exile that spell as it resolves. Activate this ability only once each turn.