Origin of Captain America

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Put a +1/+1 counter on target creature you control. It gains first strike and vigilance until end of turn.
II — Create a colorless Equipment artifact token named Sturdy Shield with "Equipped creature gets +1/+2" and equip {2}.
III — Tap up to one target creature and put a stun counter on it.