In the Alpha, every time I took Mystera I lost the dungeon. EVERY SINGLE TIME.
Try using all your health potions against the boss, saving your mana potions, then worship Mystera at the last hour for her "magic" boon to boost your spellcasting power. She's an 11th hour god in the alpha; not a very good one, but she works.
Out of curiousity, was the Halfling and Gnome really considered "weak" enough in Alpha to warrant the 80 conversion rate they are getting in Beta?
Back in the alpha, level-up catapults were much
more critical to your approach against the boss, so elf and dwarf tended to get significantly more mileage than gnome and halfling. I didn't use the potion races in the alpha unless it combo'd off of one of my class features.