The most dangerous weapon in the wandering inn 10.10
Now, to begin with, as stated time and again, wars are won on the backs of logistics. Granted, with levels and skills, this greatly changes things as a swarm of enemies can easily be beaten back if they are painfully low level vs a group of high-level people. That said, armies still need to march, high-level people still need to rest, people still need to eat, and in a pinch, defenses never hurt. Which is why, in my humblest opinion, I believe the greatest current (not one-time use) weapon is the wandering inn itself.
Given the list of abilities and skills placed into the inn, it would make it a powerful mobile, defensive, logistic's wetdream, center of command and operations. Given its ability to not only store but also preserve food and equipment in both vast quantities and indefinitely, it is merely a question of how large and dedicated you use the space for storage, since every bag acts as a bag of holding. (and noted this was at level 40) This doesn't even touch on the storage space in the gardens of the sanctuary itself or its food production capability.
Next is the theater, which allows you to spy on the enemy, observe fights, relay orders privately, or serve as a moral booster, ie entertainment. After that, you have a [portal door of 500 miles], which, coupled with sage grass and [magical grounds], allows the swift movement of troops and supplies to where they are needed. The inn itself has [reinforced structure], [partial repair], and now high-quality material to make it impressively strong and defensive, which means it's a fortress in its own right, and the ability to repair itself makes it hard to destroy or break into. This is before even considering magical defense or extra weapons placed about.
Finally, a [two-fold rest] and [local authority: building] will allow high-level soldiers or commanders to rest quickly so they may be fresh or energized for tough or quick, rapid engagements. while the building itself, in theory, will help defenders themselves or keep on the move.
TLDR: This, of course, does not tie into a few of the newer skills as they have yet to be touched on, but clearly makes the inn a terrifying weapon of war should it choose to be. keeping troops well fed, well equipped with fresh gear, and moved around at lightning speeds across hundreds of miles, fresh and energetic, while providing real-time eye witness and overviews of the battlefield, communication, and spying, then Finally Finally a mobile, heavily fortified, magically positive weapon for mages to use rituals or cast from to break armies upon.