Combos Utilizing Memory-Crystal

whim changes forest on lifetap to land type opponent taps the most of. gain 1 life for each of that land type opponent taps. buyback whim for 0 (cuz of crystal). repeat

whim changes mountain on lifeblood to land type opponent is playing. gain 1 life whenever that land type is tapped. buyback whim for 0 (cuz of crystal). repeat

tap compass to make opponent's land a swamp. enchant it with algae. play mind games to destroy enchanted land. buyback mind games for u. repeat next turn for 1guu mana

With 2 memory crystals, lab rats buyback is 0. Play lab rats, sac the token to the altar for 2 mana, convert to black, make 2 rats. Repeat infinitely.

cast l.rats to produce a tokken n buy back to cast n sac

with two crystals out, and lots of mountains, searing touch deals x damage divided as you choose between any number of targets; x is # of mountais you tap. other red mana producers work too.

whim changes white on gloom to spell color opponent is playing. opponent's spells cost 3 more to play. buyback whim for 0 (cuz of crystal). repeat

memory crystal reduces buyback cost by 2. continue to return cards from graveyard to hand for 2b.

with memory crystal in play, buyback cost on capsize and shattering pulse is reduced to one colorless

put villian in play. if opponent isn't playing blue creatures, cast whim to change blue to his creature's color. tap villian destroy creature. buyback whim for 0 (cuz of crystal). repeat