Titus

Titus is a human that serves under the banner of the Abyssal Legion. He is one of, if not the strongest, character to appear in the series and was the one to sever an arm of the highly evolved monster Garralosh before the latter escaped. The wound did not regenerate due to the injury having been inflicted with Titus' cursed axe. It's confirmed he fought in sixth strata.

Power
His effective strength varies greatly depending on mana density of the area. He needs great saturation of mana in his cells to safely channel his skills – second strata pre-wave mana levels were insufficient for more powerful ones, resulting in great strain to his body after utilizing one of them during Siege.

He fought multiple times against Garralosh in the first strata, most important of the fights lasted hours , eventually ending with Titus's victory and monster's long-term mutilation. Despite one-sided result, both the length of the clash and the lizard's successful escape indicates that Titus, while severely restrained by first strata mana levels, and Garralosh, prominent monster of at least sixth tier, were quite evenly matched. This is reinforced by Morrelia's comment during their reunion, as she considers Garralosh only actual threat to Titus in both first and second strata.