Add Archnemesis rares to Private League options

Hi, a long time player here, reminiscing some of the good old times. Archnemesis did not find a permanent place in PoE, but it could be as an option to Private Leagues to replace the standard rare monster modifiers with Archnemesis mods. The Vision for meaningful, quick to glance mods, and loot galore, could still be worked with and made possible for those who want to challenge themselves. Other moddable games, like D2, Grim Dawn, have mods that change the rare monsters to spice thigns up a bit for veterans, so I thought maybe some would be interested of this in PoE.

Now that the suggestion is out of the way, my general opinion of Archenmesis mods is that they were fun and identifiable, but overtuned in power way too often. At some point every map had at least that one Archnemesis monster, that was not God-touched, but was still wrecking places. For GGG to have some control over how often an Archnemesis monster is overpowered, the overpowered monster should be the God-touched as a baseline design. As an example, all Archnemesis mods should be at 50% effect, expect when it is a God-touched, when they will all be at 100% effect. Other fun balancing steps is to limit magic monsters to 1 mod and rare monsters to 1-3 mods, but allow an extra space for a mod when it is a God-touched.

PS: I'm reminiscing how the rares were in 3.19 Kalandra League, just to give a point of reference.

PS2: GGG could also use this option in some races and events to make things exciting and "new".