Protheus is the final boss of the 3-man Adventure Thais Temple. He is a Elder god of Aelion who has dominion over the sea, and whose mind seems to have gone array. He has somehow managed to influence those of the Oceanide race that remained stranded on Aelion due to previous invasions, with the Oceanides taking interest as he is a god who is aquatically inclined.
In his madness, he and the Oceanides harmed devout temple-goers of Thais Temple. His madness is obvious when one observes his mannerisms in the way he speaks. When the Immortals engage Protheus in combat, he sometimes proclaims that he does not wish to fight them, but will if he must; that they (the player) do not understand what he is doing...
He is one of the main reasons for the current invasions from the Oceanides home planet of Olghul. His control over the Oceanides on Aelion has captured the attention of their Great God Tol-Monter, who along with destroying the surface dwellers of the planet, also wishes to capture Protheus, absorbing him and his power over the waters of Aelion, allowing him to regain full control of his stranded Oceanide race. A race that is rightfully his.
Massive Summoning First, Protheus summons Khelps but remains out of reach. When he joins the battle, Protheus keeps summoning a pair of Icy Abyss Khelps, spending some of his power and thus becoming vulnerable for 8 seconds. Ranged ability. Frequency: none. He summons new ones when the previous ones are defeated.
Summoned Naiads Protheus summons two Naiads that can slow the enemy down. Ranged ability. Frequency: none. He summons new ones when the previous ones are defeated.
Water Barrier Protheus, hidden behind the barrier, takes significantly less damage. Melee ability. Frequency: none. He remains behind the shield for most of the fight, dropping it only when summoning minions.
Protheus' Powerful Strike Protheus has the strength of a god. He will slam his two-pronged trident upon his current target whenever he is close enough to do so. This will almost always one-shot the player, unless they have some form of damage mitigation. Protheus will never attack while he is weakened. He will summon Khelp during this phase.
Lightning Strike: After losing half his health, Protheus' head will become covered in water and will stop slamming his trident, instead, he throws a powerful but easy to avoid lightning beam.
Strikes the enemy position with a lightning bolt that inflicts significant damage on impact. Ranged ability. Frequency: 6 seconds.