Refills all heart containers. Grants an enormous damage boost that wears off over time.
"Full HP + temporary DMG up"
On pickup, fully heals Isaac and gives him a temporary +21.6 damage up.
The damage upgrade scales down to 0 over the course of three minutes. Due to how the damage formula, works, the damage upgrade scales down faster over time, starting at -~0.015 per half second and increasing to -~.1 per half second as the bonus approaches 0.