When Doomskar Titan enters the battlefield, creatures you control get +1/+0 and gain haste until end of turn. Foretell {4}{R} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

When Geological Appraiser enters the battlefield, if you cast it, discover 3. (Exile cards from the top of your library until you exile a nonland card with mana value 3 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

You may have Mirror Image enter the battlefield as a copy of a creature you control.

Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.) Channel — {2}{U}, Discard Mirrorshell Crab: Counter target spell or ability unless its controller pays {3}.

({T}: Add {U}.)

({T}: Add {G}, {U}, or {R}.) Ketria Triome enters the battlefield tapped. Cycling {3} ({3}, Discard this card: Draw a card.)

({T}: Add {R}.)

({T}: Add {U}, {R}, or {W}.) Raugrin Triome enters the battlefield tapped. Cycling {3} ({3}, Discard this card: Draw a card.)

({T}: Add {U} or {R}.) As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.