When Diana's head was visible he directed everyone to strike with everything they had.
Hitting her critical point was not as effective anymore due to her aura somehow distributing the damage across her whole body.
Their combined damage took her down to ~95% hp.
They had a well prepared plan.
While she was summoning her undead they would target her head as often as they could, War God would handle the warrior skeletons and Ezekiel would add extra magical damage to take them down.
When she was casting her spell to summon her undead Shade would do his best to interrupt her by striking her with his assassination skills.
Hope was the one who would watch their backs and heal them when necessary while the others would make sure she was defended.
Their teamwork was not really refined as they hadn't worked together much before that... except for Shade and War God that is.
Their efforts were rewarded as they brought the boss to 50% which began the next phase of the fight.
Soon a giant skeleton that was almost scraping the ceiling with its head appeared.
Infused with shadow mana it struck out with a sword made of shadows and a shield made of green.
This new summon was more problematic than the others as it moved quickly, it hit harder and it was far more resilient than the rest.
Its blade struck his mana shields hard which only made him fly back into the wall of the mausoleum but he didnt take as much damage.
While trying to recover from the hit he saw that the giant warrior skeleton was beating down his allies.
When War God tried to block its sword she was slammed back by the shield and when Shade tried to strike at its neck to decapitate it the skeleton released a strange burst of shadow mana.
The mana covered Shade and incapacitated him temporarily while the rest were trying to harm her.
The summoning of this skeleton was so unexpected that it had broken their plan down.
Soon enough the blows from the skeleton and the spells from the boss overwhelmed them.
They all got back together outside of the dungeon and planned to meet up outside of the territory to train.