this game is ridiculously hard, I end up having to higher henchman every day.. and cant get past day17 casual with my henchman and 2 other hired soldiers..impossible to save cash and castle gets destroyed in seconds
couple of tips:
blade combo+ life per kill/mana per kill on items work like a charm as you use blade combo that does if i recall correctly 16 fast hits(at max lvl that is) and if mob is low health each of those hits would count as a finishing blow as if you have killed 16 mobs=replenish mana and health very fast.
level bit of str and loads into luck at the start+as someone said %drop rate on items(+2 on each of them to save up crystals)
Check rare stuff merchant every time in town cause he sells best of jewelry+belt available in game(it doesn't change over levels and the stuff he sells has enchantments+ base compose ammount as if it wasn't enchanted)
Have fun.