When Cyclopean Titan dies, two target lands become Swamps. Exile Cyclopean Titan. {3}, {T}: Tap target creature, then return Cyclopean Titan to its owner's hand.
2019-11-12
If a land becomes a basic land type (such as Swamp) but not "in addition to its other types," it loses all other land types it has and all abilities from its rules text and it has "{T}: Add {B}."
2019-11-12
If both target lands become illegal targets, Cyclopean Titan's triggered ability won't resolve. It will remain in your graveyard.