|The necro kept poisoning the enemies all the time, and the Dark Demon got to the killing from the very beggining against the enemy Barb.|
In your case, by the time you got to hit the enemies your Succubis and Horses were almost dead by the Wizard's magic.
Your friends did way better imho tbh.
Try taking Battle Fury and playing more aggresive maybe, your enemy was a Wizard, so its not like he was going to offer a lot of melee resistance, since the enemy Barb wasnt gonna help, he was facing the Dark demon.
Just my opinion from the battle though.