832nd idiot to reach 15th level. 7 cantrips, 5 shields. Minimum of 12 upgrades (6 cantrips/6 shields also seem to be viable) are probably necessary. Once you have the upgrades and the right strategy, the only thing you can do is pray and hope the cards fall your way. If not, try again and again.
Always look for spaces for you to escape, unless you can finish the floor this turn. Then plan your attack.
Late game quick leveling up: Send only Ice wizards (#8) and turtles (#5) in 5-19, stay back and use Undead Mace on the mummies that come. Don't kill the King Mummies, you want them to summon the little mummies that will rack up your EXP points. I leveled up from lv 80s to 200 (max) in a little over an hour.
 "Pawnbarian"){kind=icon}
 "50 years (graphical)"){kind=icon}
 "Tough Love Machine"){kind=icon}
 "Paladog"){kind=icon}
 "Accelerator"){kind=icon}
Achievements will be updated. There are no secret achievements )