Oath of DaBossMan

When Oath of DaBossMan enters the battlefield, look at the top 4 card of your library. You may reveal an instant or sorcery from among them. Put it into your hand.
Whenever a planeswalker you control is attacked, sorceries in your hand gain flash until end of combat. You may play an instant or sorcery for {x}{u}{r} less, where X is the attacking creature's power. Do this for each attacking creature.
So that nothing shall be forgotten, I will keep watch.