Oath of Ajani 
Legendary Enchantment
When Oath of Ajani enters, put a +1/+1 counter on each creature you control.
Planeswalker spells you cast cost 
less to cast.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL