Have

Commander Liara Portyr

Whenever you attack, spells you cast from exile this turn cost {X} less to cast, where X is the number of players being attacked. Exile the top X cards of your library. Until end of turn, you may cast spells from among those exiled cards.

Quintorius Kand

Whenever you cast a spell from exile, Quintorius Kand deals 2 damage to each opponent and you gain 2 life.
+1: Create a 3/2 red and white Spirit creature token.
−3: Discover 4.
−6: Exile any number of target cards from your graveyard. Add {R} for each card exiled this way. You may play those cards this turn.

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Plains

Mountain

Warehouse Thief

{2}, {T}, Sacrifice an artifact or creature: Exile the top card of your library. Until the end of your next turn, you may play that card.

Master Warcraft

Cast this spell only before attackers are declared.
You choose which creatures attack this turn.
You choose which creatures block this turn and how those creatures block.