Please find below a list of possible Excarnus Strategies and other info.
All of which the above should be level 95+ which allows those at level 95 to have 5 abilities fully maxed if that were their choice.
As for a strategy, killing the summons will make your life and your two eni's lives so much easier. Although, when a monster is killed, it's bones are left behind and are able to be revived by excarnus. prevent this by destroying the bones also. Be sure to stay near each other and know the range and capabilities of your eni's don't be a hero, they won't ensure your survival for stupidity.
Once the summons are removed (as well as the bones) you can attempt to hit excarnus, have an eni close by to the damage dealers, and one by your long range damage dealers as while you're hitting excarnus, summons will appear anywhere on the map, leave no room for surprises. As the summons appear, destroy them immediately (including the bones).
With practice, teamwork and luck, this is completely possible and i wish you the greatest of lucks.
P.s. bring your lucky rabbits foot.
I noticed that when you destroy both totems he brings them back the next turn, it doesn't cost him wp either.
There are 2 different stuns in this fight, the first is from the evil totem which cant be cured by eniraser and the second is from the summons and those can be cured. The undead gobballs and remains have the undead status and can be damaged with heals.