@Questor would you be able to give us some details about Merlin's Illusion capabilities?
What he can do immediately, what he can do with 10 minutes of preparation, what he needs hour+ long Rituals for, etc.
Would he be able to create a moving image of the army going one direction while we all retreat a different way?
Of the illusion army suddenly catching fire and fleeing, while the fire builds and builds until it rages towards the Major, while we retreat?
@Player Base, our win condition here is Minimum Losses.
The Ursa Major
broke out of a Mountain.
Its size is comparable to Mountains.
Unless we send a dedicated kill team to fly into its ear and burrow into its brain, we aren't actually going to be able to do much of anything to it from the outside, and only suffer many many deaths.
If I'm incorrect about the size then I ask
@Questor to correct me.
Our goal should either be to retreat altogether or to swiftly create an Adventuring Party to plant some Explosives into its ear canal to kill it/significantly wound it, while everyone else runs away.
In that case, I'd go for a mixed Griffon/Pony/Diamond Dog squad, for transportation to the ear, identification of the best spot to plant the booms, and transportation within the ear respectively, while Merlin provides the army with a distraction for the retreat and possibly a portal exfiltration on what would otherwise be a suicide mission.
@Questor do we have the components for such a slapdash plan to be vaguely feasible?