They can’t leave the city, so that’s out. Also even on a full noon sun blasting down on, he probably wouldn't go down fast enough to avoid damage/civies, we just got a glimpse of him going full power before he got trap. our ”heros” are also trying to avoid attracting attention because they using the fake hero for monetary gains(money that was gained from “defeating“ a dragon who’s now in their party btw)
don't think we have been showned how the wardrobe ownship could transfer over or if something would happened to the dragon if the will is taken out of the city too so fake hero can’t just take the Wardrobe outside the city too dispose of the vampire in the comfort of a desert.
You're right I forgot they aren't allowed to leave the capital.
So change of plan, have Mithra do whatever she did in Chapter 2 that allowed her to fly into the capital unnoticed, but instead fly as high up as she can and do what I wrote before and aim upwards and blow him up in the clouds and nobody will think to look high up to see what's going on before it happened already.
She will have to do this alone and might possibly lose some clothes but still better than going into the closet where all the clothes are.
And I'm talking about a fully charged blast that she sneezed and fired early that was able to disintegrate a mountain. I can't imagine believe Mr. Vampire upon seeing the door open and flies out to be greeted by the blast can survive that unless we're in Bleach Reiatsu territory where as long as your Reiatsu is higher than the other guy, even if the planet is blown apart by their attack you'll still be unscathed in the rubble, and a single punch from you will take down your opponent and not damage anything else.