Complex sentence: A challenger must defeat three of its "Gladiators" in order to face Brakus, but Travis challenges Brakus and amused by Travis's arrogance, Weldon grants his wish.
Split into simpler sentences: A challenger must defeat three of its "Gladiators" in order to face Brakus, but Travis challenges Brakus outright. Amused by Travis's arrogance, Weldon grants his wish.