Nyxborn Twilight Sparkle

Bestow {3}{w} (If you cast this card for its bestow
cost, it's an Aura spell with enchant creature.
It becomes a creature again if it's not attached.)

Mentor (Whenever this creature attacks,
put a +1/+1 counter on target attacking creature with
lesser power.)

Enchanted creature gets +2/+2 and has
mentor.