Guilds of Ravnica

Aurelia, Exemplar of Justice | Legendary Creature | Angel | Flying Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.) At the beginning of combat on your turn, choose up to one target creature you control. Until end of turn, that creature gets +2/+0, gains trample if it's red, and gains vigilance if it's white. | Chris Rahn

Hammer Dropper | Creature | Giant Soldier | Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.) | Lake Hurwitz

Truefire Captain | Creature | Human Knight | Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.) Whenever Truefire Captain is dealt damage, it deals that much damage to target player. | Chris Rallis

Conclave Cavalier | Creature | Centaur Knight | Vigilance When Conclave Cavalier dies, create two 2/2 green and white Elf Knight creature tokens with vigilance. | Tomasz Jedruszek

Sumala Woodshaper | Creature | Elf Druid | When Sumala Woodshaper enters the battlefield, look at the top four cards of your library. You may reveal a creature or enchantment card from among them and put it into your hand. Put the rest on the bottom of your library in a random order. | Sara Winters