Multiple instances of lifelink on the same creature or planeswalker are redundant.
2019-05-03 • wotc
If Sorin leaves the battlefield after you've activated his first loyalty ability during your turn but before it resolves, you'll still gain 1 life as that ability deals damage.
2019-05-03 • wotc
If a card in a graveyard has {X} in its mana cost, X is considered to be 0.