This is my mage at the end of dungeon level 9. He's level 13, and he also has two potions of healing. Two challenges are active (badder bosses and swarm intelligence). The unidentified scroll is not "remove curse" (nor "identify"). There are no more spells nor potions in the level-6 shop. The scale armor has a curse of displacement. How would you continue?
Update: I thought this was an interesting scenario, with several different ways to proceed with no obvious winner. Thank you to all who posted ideas; I hadn't considered most of them! SPD is such a complex game.
As to what I did: since BB Tengu is a PITA, I decided to dump 3 SoU on the scale armor; in addition, I was lucky and got a glyph of affection. I used the other 3 SoU on the staff, leaving the magic missile wand imbued and relying on its magic charge ability to pump the lightning and prismatic light wands. It was a hard fight but Tengu was free at last!
Then I made it through the caves without too much trouble. This is the mage at the store in level 16. I still have two SoU which I will probably use on the staff. I'd like to attempt finishing the game with an imbued wand of primatic light, which I've never been able to do before. Suggestions welcome!
I'd equip the chain mail armor. Even in the worst case, is better than the one you have equipped right now. Then I'd throw the broken staff directly above the upwards stairs, so on my way back to the surface with the Amulet of Yendor I don't forget to pick it up (so I can get the You made it too advancement) and I get an extra inventory slot for the rest of the run. I wouldn't worry about the scale armor, as it'd have to be a +3 for it to be usable at this point in the story (I think it was a 5% to 10.5% chance depending on where you found it, a bet) unless the mage quest is the the Rottenberry one, then you have the choice to (first find a blandfruit) cook it with a blandfruit to get an extra point of strength, if mage's staffs don't convince you, then the scale armor would just have to ve +1 or more for you to be able to use it.
Also, if that mail armor isn't upgraded, Tengu will kill you. You might need more mobility too for the badder bosses Tengu, he sometimes throws unavoidable attacks at you unless Ring of Haste +2 or Ethereal Chains (and by sometimes I mean all the time, and by attacks I mean the fire gas one. Maybe try to get brimstone glyph. If you get hit by the fire gas while you are wearing an armor with the brimstone glyph, you won't be eligible for the Gotcha badge, btw)
Then I'd choose warlock because I'd rather restart the run than being forced to use the staff as my melee weapon.
Then I'd search for a plate armor before I get killed by the mines' enemies (or, if the scales is good enough, I might get to goblin city, then same applies) and bump my upgrades into it. And then I'd just win, if I don't do anything stupid near the stupid floating eyes.