He lied....After you found out kaeya was the descendant of the abyss order.he patted your head and promised that he will take the abyss down..

it was broken. There was now monstadt in flames and screaming and monsters everywhere..

After That.You became like dainsleif and met a traveler who had a flying companion..

At the end..

monstadt was in flames and fire And monsters were there...There.You were on your knees heavily injured and kaeya,the now king of abyss was holding your hair.

".oh izu..You promised to protect monstadt from me and look...makes me chuckle."

(user is Male!!-)