Yashur, you're overthinking it. Just run up and attack, preferably Shaila. Ushumgallu has a "last stand" ability when his HP is below 1. If he has any other skills, check his stats and activate them as needed.
He messed up on the second turn: firstly, he didn't consider that Illiman would also move and stand next to him, secondly, that he could have attacked him, and thirdly, he misunderstood his skill. I thought that "on the line of attack" meant that if he attacks someone, he attacks everyone on that line, but it turns out that's not the case...
So, Ushumgallu got hit... just like that...

Now I see that I can move up and attack Shaila. But then Ushumgallu will get hit by Illiman again, and on the next turn, he'll be attacked directly, since he moves later. What will happen in the end - I don't know...
Alex, I apologize for my stupidity... I don't know how much experience Eric will get from this battle, but Yashur definitely got a lot...
Ничто не возникает из ничего и ничто не пропадает бесследно.
Если где-то чего-то убудет, то в другом месте добавится.
(Закон сохранения).