What The Hell Is Going On!

After pulling the blade from Yang's back her attacker adjusted the blade for an attack on Marcus only for a shadowy force to leap out of his chest throwing her all of the way across the temple and right through the doors. The person then stumbled backwards before gaining her footing and fighting off her attacker. Who was the attacker and who was being attacked?

"Ying what happened?" called Lilly as she drew her weapon and started towards were Ying was fighting off a shadowy creature.

"No! Lillian you all are to stand down. Ying made her choice now she must live with the consequences of those choices." called Fang from the temple's shattered doorway.

"Sir? Ying is your daughter and that is an Arilust! You can't be serious about standing down." exclaimed Lilly still ready to leap into the battle.

"Should we not summon back the arch mages?" asked Char-Ra as she too got ready to leap into battle.