[lloeki]

My memory is very blurry about it but IIRC in Skyrim you can reset your build with a spell or something, and even change class with a side quest (possibly even appearance, or even race, but that one may have been a mod), so you can really do everything in one playthrough with one character (Ship of Theseus notwithstanding)

IIRC a couple of quests had branches that were mutually exclusive on some conditions though (mostly either you get reward A xor B)