Call of the Full Moon | Enchantment | Aura | Enchant creature
Enchanted creature gets +3/+2 and has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)
At the beginning of each upkeep, if a player cast two or more spells last turn, sacrifice Call of the Full Moon. | Nils Hamm
Infectious Bloodlust | Enchantment | Aura | Enchant creature
Enchanted creature gets +2/+1, has haste, and attacks each combat if able.
When enchanted creature dies, you may search your library for a card named Infectious Bloodlust, reveal it, put it into your hand, then shuffle. | Zoltan Boros