Now i HAVE to make a choice between them...

Your opening post certainly sounds like you're not enjoying Luminous now. So don't play him. But you don't have to think of it as a death sentence. Just a suspension. Nexon always makes changes, big and small, and at some point Lumi might become fun to you again.

Also, with the level cap being raised to 250 soon, you could keep grinding your I/L pretty much forever, as long as you enjoy it.

Agree.

Lvl 200 is always my goal, it would not change even the cap is raised. So I would not train my I/L any further than lvl 200, unless Nexon does something better to us, or I invest heavily in this game, which is impossible for me to do that.

But I digress. It is a significant nerf for us, and it impedes us greatly. Why don't you finish up your CL, then come back to your Lumi?
Hadriel

Because a magician class as a main is pretty much enough for me, i wouldn't like to have another one that shares my love with my I/L

Nonetheless, the duration nerf is redundant imo..