ONE PIECE Episode: 377
Manga Chapter: 485
Strawhat Pirates have defeated one of the Seven Warlords of the Sea. Before they could celebrate, another warlord comes to take their lives. Kuma easily defeats them and offers to spare they lives if they hand their unconcious captain Luffy to him. They refuse and he knocks them out. Zoro gets up and fights him but the difference in power was clear.
Zoro knew they're losing he offers his life for his captain and friends. Sanji gets up and offers his life instead but Zoro knocks him out to save him. Kuma decides to test Zoro's resolve by giving him Luffy's pain.
Kuma turns Luffy's pain into a physical bubble with his ability to and gives Zoro a small taste of it. Zoro collapses from the pain of this tiny bit of Luffy's pain. He decides to move to somewhere else, expecting to die there.
A while later, Sanji wakes up and looks for Zoro, and finds him a bloody mess. He asks "Where did the warlord go?" "Are you alive?" "What the hell happened here?" Zoro answers, in pain: "Nothing... Nothing Happened."
This Badass scene proves why Zoro is one of the Top 3 One Piece characters!