Heartless Summoning

Creature spells you cast cost {2} less to cast.
Creatures you control get -1/-1.

Brighthearth Banneret

Elemental spells and Warrior spells you cast cost {1} less to cast.
Reinforce 1—{1}{R} ({1}{R}, Discard this card: Put a +1/+1 counter on target creature.)

Sneak Attack

{R}: You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.

Bloom Tender

Vivid — {T}: For each color among permanents you control, add one mana of that color.