Nothing absurd, but I guess something like Oblivion or Fallout 3. I like games with more stats and more choices at leveling up.
Oh and importantly, a really good leveling system, preferably something with stats as well as skills and perks.
Crafting/building from Fallout 4/all of the crafting games that are already out there, there are plenty to look at for ideas. Story and character development of Witcher games. Massive world and freedom from Skyrim/Oblivion, magic from Souls/morrowind. Take all the weapons from Skyrim, DS 1 and 2 and Bloodborn and throw them all in one game. Item variety from Dark Souls 2 with both xpansions, as in, a lot of different weapons, with different attack styles and animations, even more than DS2. Combat from Souls/Bloodborn, as in use both styles in the game just balance light and fast weapons vs heavy and slow ones, mix in some elements from Witcher 3 as well as Mount and Blade if possible.
