Morrigan is one of the best cards in the game, so gold star for you. There are no other "vampiric" cards that give an opponent's health to you, and in conjunction with clear-away-blocker cards (Peacemaker, Puppet, Reparation, Double KO, and big guns like Akuma and Yamazaki), it's often not too hard to get that clear shot with her.
If you can get ahold of a Rose or two, do it. Her power (draw four cards, discard three when Rose is played) is just plain awesome for getting better cards at critical times. (Best Shot is sort of a low-budget version without the B rarity.)
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