Raid Duel - The Flames of Vengeance: Ccapac Apu is an event in Yu-Gi-Oh! Duel Links. When in effect, Kalin Kessler appears as a temporary opponent, who can be Dueled in order to claim multiple rewards, including the ability to unlock him as a playable character.
The player must be at Stage 4 or higher.
Collect Dark Signer Vestiges by defeating Duelist in Duel World and Ranked Duels.
Use Dark Signer Vestiges to Duel Kalin Kessler.
Synchro Monsters do double damage in Raid Duels, Signer Dragons do Triple, so use a Synchro deck that can deal a lot of damage in a short mount of turns!