Ele pen and ele weakness curses

I've been googling this, but I still can't quite grasp it, lol.

Now, from what I understand, ele pen doesn't actually lower the enemy's resistance. It just bypasses it.

So how then do the reductions of the ele weakness curses factor into it?

The problem is I don't even know how mob resistance works. Are they capped at 75% like us? Can they overcap and make Ele Weakness redundant the same way we can?

It's all very confusing. Here's my basic dilemma: I'm doing a Ngamahu build with 100% fire conversion, and I'll have pretty high pen, something like 80-90% with Wise Oak. So would running Flammability and Ele Weakness be a big DPS increase? Or would it somehow, due to all these mysterious mechanics, not even be noticeable?

Mob resistances work the same way as player resistances, first you add and subtract all your resistances, then if it is more than 75% it goes down to that number and then elemental penetration start working.

Yes, they can overcap, but they don't do it naturally, it only happens with map or mob mods. It is really easy for ele weakness to become redundant on bosses on a map with ele resistances.

With that lvl of penetration I would recommend you going for other curses. The most you can get from a elemental curse is like 30% more damage with your setup. It will be much better for you getting enfeeble or temporal chains, or even Assassins Mark if you really want the absurd dps.

Thank you very much, that's exactly what I wanted to know. I'm non-crit, so I think I'll go enfeeble + HoA, or maybe blood magic keystone with Essence Worm + HoA.

Thanks again. :)