He was highly skilled in melee combat and could cast the most difficult wizard spells.
When Gorion's Ward arrived to clear the enclave, Egeissag's unusual spectator made a suggestion to the captain. The beholderkin suggested that even if he and his group slay the ward, the credit would go to Sendai, so the captain should challenge him to one-on-one combat. Egeissag saw the wisdom in the beholderkin's suggestion, as when Sendai reported successful, she would tell the matron mothers that it was all her work. The terms were that whoever lost would perish amongst everyone else they were allied with in the room. If the duel was accepted, the spectator made use of a geas spell, so that the terms of the agreement were absolute.
Ultimately, the ward won the battle, and all of Egeissag's allies died, except for the queer spectator. The spectator, of course, didn't subject himself to the geas. He went off to "find the nearest hive" and "check out the ladies".