Flash
Enchant creature
Enchanted creature gets +1/+2 and has vigilance.
Addendum — When Sentinel’s Mark enters, if you cast it during your main phase, enchanted creature gains lifelink until end of turn.
If an effect copies a spell with an addendum ability while it's on the stack, the copy wasn't cast at all, so you won't get the addendum bonus.
25-01-2019
wotc
Gaining vigilance any time after the moment you choose to attack with a creature won't cause it to become untapped, and losing vigilance after that time won't cause it to become tapped.
25-01-2019
wotc
Multiple instances of lifelink on the same creature are redundant.
25-01-2019
wotc
If Sentinel's Mark enters the battlefield without being cast, the addendum ability won't trigger, even if it's your main phase.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.