Heh, that's funny. Cool that someone still remember game. Now i on evil versions of main characters, and i don't know how to kill evil Natalie.... A lot of limits🤔
I didn't have all challenges enabled, but I gave NoLegs fire immunity (accounting for 100% weakness) and some holy protection. I made him unhittavle with high dodge and used mirrors for enchantments to survive limit breaks
Natalie limits you from using any healing skills, but not the healing from items. Stack up on healing items (but you probably have enough by the time you get to natalia)
The real challenge with Natalia is tanking her elemental attacks. Since she only uses Fire and Holy, you can stack tons of resistances to both and wear her down.
One tip that I can give you is to fight every foe on screen (that you can reach) atleast once. A certain friend of mine didn't do that and struggled with the final boss. Also I only hand out my discord to friends and family
