
If you would lose unspent mana, that mana becomes colorless instead.
Horizon Stone has 3 printings, first in Commander Legends (2020). EDHREC ranks it #4,147 among Commander cards. It appears most in Yurlok of Scorch Thrash decks (8,548 on EDHREC). It has 2 official rulings.
Deck counts from EDHREC.
Cards that show up in the same decks on EDHREC.