
My first run was with JJ, and I got to 40 mana but it wasn't much use for me. My conclusion was that despite the lackluster mana boosts, Mystera is still better, thanks to the much-better timed mana refills and, well, Tinkers being Tinkers (as in, getting awesome items!

EDIT: oh, and I almost abandoned the run early on. I started in an enclosed area, and had no glyphs to get out / generate Mystera piety; I prepped the Bear Mace, but I couldn't find any monster to hit without suffering some adverse effect like Weakness (a bit to steep of a cost just to move a guy out of the way); all I had were my seals. First shops had items I didn't fancy like Bloody Sigil and Troll Heart, and I found two glpyhs - BYSSEPS and IMAWAL - and got a bit annoyed, because - again - neither were glyphs I particularly fancied (or could even just spam for Piety). So I was really constrained and considering to just re-start the whole thing (I went to do some stuff and just left the game running, as this felt like, probably, the worst Naga City start I've had, and I've played and re-played that map dozens of times).
So when I came back, I decided to give it a shot, because I really hate abandoning runs. So I used one of my seals to break a wall that looked thin, and I got into a bit bigger area that had the shops with the Mage Plate and the Dragon Soul, as well as APHEELSIK. Things started to look up then, as I know that APHEELSIK is one of the best non-damage glyphs for the Arena, and makes some of the bosses much easier to fight. Furthermore, I uncovered a low-level dragon which I could finally start slapping into walls to break up the map a bit, and it gave me enough breathing space to get to some more shops and boosters. When I found the subdungeon (it was the signpost sub that gives the extra Mana booster!) I felt that perhaps this run was fated to succeed despite the hard time the beginning gave me.
Of note is that I did not find PISORF (which would have made the Arena battles much simpler), but the combination of BURNDAYRAZ and APHEELSIK proved to be sufficient to take out all bosses (I used three or four Weakenings against The Iron Man, as my JJ run ended when I couldn't penetrate his magic resistance with fireballs alone). I also did not follow any efficient leveling, and IMAWAL-boosted killed Glenrick at L1, which cost me a lot of piety (on top of the piety I lost due to not having any glyphs early on), but the level boost more than made up for it.