Combos-

infinite mana-
1) caged sun/high-tide x4 into archaeomancer/shipwreck dowser/salvager + ghostly flicker (on them+land) + other targeting spell
2) mindgames/clockspinning + peregrine / powerstone shard (with 4+)


then reality shift x infinite (if they have a creature each)
or blue suns for infinite
or with mindgames/clockspinning (soft)lock with agent of treachery / imprisoned in the moon

Other win-cons-
1-Flash in torrential gearhulks before turn start to have an army of beaters
2-multiple murmuring mystics or Master of the waves.