Putting myself in Serini's shoes, she had a stable situation going (Team Evil wandering from dungeon to dungeon and making no signs of progress). Now a bunch of do-gooders who haven't objectively done much good, as far as the Gates are concerned, is on the verge of cluing Team Evil in on the whole secret of the dungeon, with one ambush that has at best a 50/50 chance of success; maybe worse, since only 1 of their confrontations with Xykon ended in a win, and then they failed to close the deal. And blew up a Gate in the process. They're troublemakers who are barging into her house and rearranging the furniture.

Honestly, I can't see a player in that situation not behaving pretty much as Serini does. In her own mind, she's the PC here and the OOTS are bit players who mess things up wherever they go.