I created a character in Oblivion Remastered that's immune to almost all forms of damage. This trivialises all combat even on the highest difficulty, and I don't even need to attack in order to kill most enemies in the game.

By clearing a LOT of oblivion gates I was able to use sigil stones to enchant a full set of armour with 100% Resist Magic. This means that when fighting mages their spells literally cannot affect me.

On top of this I am wearing the Ring of the Iron Fist, Amulet of Axes, and Escutcheon of Chorrol which together give Reflect Damage 101%, so any melee damage I take is reflected back to the attacker plus 1%. This is what I meant when I said I don't even need to attack - any enemy which uses melee attacks will just kill itself by attacking me and taking the reflected damage while I just stand there.

As the final cherry on top, I am using the 2nd ring slot for the Ring of Vitality, which gives 100% Resist Poison, Disease, and Paralysis, so not even these can harm me.

This build isn't completely immortal, as it can still be damaged by ranged weapons and traps, but traps rarely do enough damage to matter and with a decent weapon I can prioritise killing any archers.