You don't choose a target nonland card at the time Memory Vampire's last ability triggers
If you pay the five mana and give an opponent a card, you get to make a 1/1 token copy if that creature was nonlegendary, enjoying that creatures undoubtedly killer EtB effect all over again
1-Turn Win Line Objective: Leverage leftover mana after casting [[Necropotence]] or [[Necrodominance]] to win during the same end step
We rarely get Dimir Vampires, and Elusive Tormentor is a brilliant design
Blue and white center on going over your opponents heads with flying creatures, while mono green (my favorite and the best way to play) favors big, stompy creatures that run over your opponents defenses
Even then, it may still not make the cut, depending on the needs of your deck and its strategies