Cascade Bluffs

{T}: Add {C}.
{U/R}, {T}: Add {U}{U}, {U}{R}, or {R}{R}.

Captain Howler, Sea Scourge

Ward—{2}, Pay 2 life.
Whenever you discard one or more cards, target creature gets +2/+0 until end of turn for each card discarded this way. Whenever that creature deals combat damage to a player this turn, you draw a card.

Mountain

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Island

Sol Ring

Command Tower

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)