Hero's and Elite Skill Use

My level 15 Koss never uses his elite skill, Gladiator's Defense. Any ideas as to why?

He has the following skills: Gladiator's Defense [E], Deadly Riposte, Sever Artery, Gash, Final Thrust, "Watch Yourself!", Healing Sig, and Rez Sig.

If I recall correctly he has 12 tactics and 10 swordmanship with the remainder in strength. And yes, he is wielding a sword.

Come to think of it, I have never seen him use Healing Signet either.

I gave Glad's Defence to Melonni when I first played through and she used it often enough. Don't know why Koss wouldn't be using it.

What order are the skills on the bar?

Maybe he isn't being attacked?

what mod was he in
offensive, defensive, or aviod

yes i have never seen my Koss heal with lions comfort either