Living Lore

If an instant or sorcery spell puts Living Lore onto the battlefield, that spell is still on the stack while you choose a card to exile. You can't exile it with Living Lore.

If a spell has {X} in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.

Living Lore's last ability will trigger whenever it deals combat damage, no matter if that damage is dealt to an opponent, an opposing planeswalker, or a creature it's blocking or being blocked by. You choose whether to sacrifice Living Lore as that ability resolves. If Living Lore has already left the battlefield, perhaps because it was dealt lethal damage at the same time it dealt damage, you can't sacrifice it.

If Living Lore leaves the battlefield, the ability that defines its power and toughness will lose track of the exiled card. Its power and toughness are 0 in other zones.