Notes:

In her defense, there's no other choice besides killing the magic. As stated by Star, magic creates problems or make older ones worse. BUT if they didn't do that & go attack the Solarian soldiers head on, they pretty much headed for suicide. Note that ONE Solarian could take out most of Star's friends (+Star's Rainbow Mech suit) with their magic sword that could make them explode over-time. They took down that Solarian that caused the trouble, but that takes most of the party's energy, all of the town's explosives, and using Eclipsa's unnamed spell. Also, Eclipsa's unnamed spell could possibly be used only once since that doesn't seem to go away.

Now IF Star, Moon, & the other pulled a miracle out of the hat to defeat the Solarian horde once & for all, Star & Marco's friends would be pretty much dead as they succumb to their glowing wounds as there's no such cure (apart from the sanctuary as River is taking Globgor). Also, the MHC are still pendejos and wanted Eclipsa out of the game because she married the once deadliest monster of Mewni whose a vegan. The ONLY PLUS SIDE on that route is no Ponyhead.