Is it sad that seeing a female character in a Diablo game, I immediately wonder how she'll get corrupted at the end/next game?
Now that I think about it, somebody at Blizzard must have a massive corruption fetish for how often it happens to all their female characters (twice to Kerrigan!) and pretty often as well to the males.
Well, there is a precedence for both players and NPC characters...
The Warrior, retroactively renamed as Prince Aidan (King Leoric's eldest and Prince Albrecht's older brother) made the dumbass decision of shoving Diablo's soulstone into his head, and he became possessed/the Dark Wanderer. He was eventually given a funeral by the Diablo II heroes in the Chaos Sanctuary by having his post-possession corpse thrown into the fires of Hell, after Diablo was defeated.
The Rogue, Moreina, came back unstable and full of mental anguish, and that resulted in her going "Yes, turning into an evil, blue-skinned necormantic babe under you, Mistress Andariel, sounds like a grand ol' idea!", corrupting her fellow rogues, and taking up the moniker of Blood Raven. She took an arrow to the
head and died in the Monastery Graveyard, and she's likely in Hell right now.
The Sorcerer, Jazreth, went mad and either came to the conclusion he was Horazon reborn or was possessed by said Horazon, calling himself the Summoner. In the Arcane Sanctuary, he was killed by the Diablo II heroes and his soul/Horazon's soul was pulled down to Hell.
Adria was retroactively made evil in Diablo III (leading a cult pre-Tristram with Maghda), despite being just a curious, Gothic-looking witch in the first game. She pledged allegiance to Diablo, got knocked up by Possessed Aidan, and eventually gave birth to and betrayed her daughter, Leah. She ascended to demonhood before being killed.
Gillian was "saved" by Adria -- she went east with her, and ended up raising Leah. The pretty barmaid went nuts over time, ending up prematurely aging and in a mental asylum.
Wirt was killed. You steal his leg and gold. Little shit.
Griswold was turned into a zombie.
The rest of the Tristram villagefolk were murdered by demons. You find their corpses.
Cain survived 1 and 2 until dying in 3.
The Diablo II heroes and NPCs got better endings. Mostly
Warriv ended up with constant bad-luck for over two two decades. On his desperate return to Tristram/New Tristram, he was killed by the Goatmen ravaging the countryside. You find his corpse and journal as a random encounter in Diablo 3.
Cassia, the Amazon, became the paranoid, new Amazon captain of her home islands: she has relentlessly trained every Amazon under her watch for a future demon invasion.
Nothing known about the Assassin.
The Barbarian was from Harrogath, which was destroyed when the Worldstone went kaboom and after it suffered from Baal's invasion, which likely killed a lot of his friends and family. Originally, the Barbarian in Diablo 3 was supposed to be the same as he in Diablo II, but this was dropped after they introduced male/female character options (because having the female character being the same as the male in 2 would've caused a little
issue or two.
So, bitter, homeless, and a wanderer.
Nothing known about the Druid, but 4 and Immortal might expand on things.
The Necromancer, Xul, apparently took two apprentices: one of them, a male, is the one you mean in the desert of Act 2 in Diablo 3. He became a highly-revered master after II.
The other apprentice was a spoiled brat called Lethes: he and the heroes in Diablo Immortal kill her, after the crazy bitch wants to reshape the world with a shard of the Worldstone.
Nothing on the Paladin, but with numerous Orders being either corrupted, killed, or twisted into other forms (like the Templars and Crusaders), it's likely all his friends and family are gone or crazy.
Isendria, the Sorceress, was killed after she tried to help people with a drought. Her spell went awry, and it ended up killing a lot of people. An Assassin, tasked with keeping an eye on her because her superiors were paranoid old men, promptly struck. They fought, and she was eventually killed after a neck-and-neck battle. Given this is Diablo, it wouldn't surprise me if her killer was her comrade Assassin, from above.
She trained the (female) Wizard, Li Ming, who suspected something like this happened to her mentor.
Her ghost can be found in the Pandemonium Fortress in Reaper of Souls. She's basically begging for death at this point, as Malthael is... well, a complete dick who upturned the natural order of life and death.
And this all isn't counting everyone who was killed, possessed, risen from the dead as puppets, corrupted, or just outright damned through the series' quests and stories.
Sanctuary is a place that pretty much punishes the heroes as a last laugh, after they "win". Blizzard can be dicks like that.