The Sky Horse Sect Leader said indifferently, "Since they've set foot on the arena, let the matters of the arena be resolved within the arena. Whatever happens, we can only watch. Everyone relies on their own abilities and accepts the will of Heaven."
On the arena, their objective was obvious—to take down the Golden Dragon Princess. For this purpose, the Eight-Armed Demon Clan was already resorting to self-detonation tactics in combat. Whether or not the self-detonation succeeded is another matter, but at least they acted that way. So, can you really blame others for playing dirty in return?
The Dragon Clan, after all, is the largest clan in the Dragon Horse Star System. Don't let the absence of the Sky Dragon Leader fool you—if something truly went wrong, that individual would likely arrive in an extremely short amount of time.