Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Whenever Tomebound Lich enters the battlefield or deals combat damage to a player, draw a card, then discard a card.
You draw a card and discard a card all while Tomebound Lich’s triggered ability is resolving. Nothing can happen between the two, and no player may choose to take actions.