Wow, I correctly predicted the ending!
I must be a clairvoyant.

So all the wars, all the destruction and death and misery, all 8 seasons, just to change Westeros from a hereditary monarchy to an elective monarchy. Interdasting

At least the ending wasn't as bad as the Star VS. ending

*Spoilers*

Star has to save SOME monsters/creatures from stuff she/her friends caused in the first place, so she ELIMINATES ALL MAGIC in the UNIVERSE.

This leads to 100%/etc magical beings poofing out of existence/dying off(Including many memorable/fan favorite side characters) while depriving many good magic users of most/all of their magical powers.

Mewni(correct spelling?) gets merged with earth, causing creatures that remain to run rampant on earth and have to be fought by the earth police/military.

All of this was done so that Star can be with Marco(to partially please fans of the ship)/save a handful of monsters from something she/others had a hand in bringing about.

(One of THE WORST animated show endings ever, imo)

*End spoilers*