Sunset Strikemaster

{T}: Add {R}.
{2}{R}, {T}, Sacrifice this creature: It deals 6 damage to target creature with flying.

Sol Ring

Mountain

Iron Myr

Cori Mountain Monastery

This land enters tapped unless you control a Plains or an Island.
{T}: Add {R}.
{3}{R}, {T}: Exile the top card of your library. Until the end of your next turn, you may play that card.

Wild Ride

Target creature gets +3/+0 and gains haste until end of turn.
Harmonize {4}{R} (You may cast this card from your graveyard for its harmonize cost. You may tap a creature you control to reduce that cost by {X}, where X is its power. Then exile this spell.)

Generator Servant

{T}, Sacrifice this creature: Add {C}{C}. If that mana is spent on a creature spell, it gains haste until end of turn. (That creature can attack and {T} as soon as it comes under your control.)

Urabrask the Hidden

Creatures you control have haste.
Creatures your opponents control enter tapped.

Seize the Day

Untap target creature. After this main phase, there is an additional combat phase followed by an additional main phase.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.