It's possible.. but you would have to sneak by a lot of the encounters, I think most late game fights would actually be impossible, one fight (the one before the ghost forest source temple entrance) is probably 100% impossible solo as he tp's you into lava ;p. But I think you can sneak by most things and skip many other things in this game.
Skills... scoundrel skills, invisibility and haste and tactical retreat. Would be vital. Aside that, obviously fire and ice magic, ice walls reign supreme... witch spells, and leech. Summons... don't think summons would save you to be honest, they barely do any damage.
But even then, one unlucky knock-down and it's over. Maybe on EASY it's possible though... with lots of luck
