Yes, that was the old canon. Then the Chronicle book for the time period he supposedly was active put him under a 404 error in the appendix and that’s the only mention of him in the whole book.
We know the comics he starred in where explicitly made non-canon. Whether that extends to him existing at all (and Medivh’s super creepy relationship with Garona having never happened) is unclear.
Regarding Zagara she is technically the child of Kerrigan and the Overmind. The Overmind created queens during the Great War (StarCraft Campaign) and Kerrigan altered queens into broodmothers after she took control over the Swarm (Post Brood War), Zagara was created first by Kerrigan.
Does this make Jimmoty Zag’s stepdad? 
Well Jimmity is Kerrigan’s boyfriend at most and Kerrigan is basically Zagara’s adoptive mother so maybe but it’s kind of a stretch
Close enough for me!
Me’dan was worse than a fanfic mary sue. That’s how bad he was.
…I mean who?
Not to discount how awful Me’dan as a character was, but the fact that he existed because Medivh, a nearly 50 year old man, had a sexual relationship with Garrona, who was force-aged by fell and less than 14 years old at the time will always be the biggest crime in his existance.
That’s every kind of wrong and needs to be burried so, so deep.
Spaghetti is straight too, until it gets hot. (glances at Wrathion’s new model)
He is being set up to go with Taelia, which is good because for some reason people were trying to ship her with Flynn Fairwind…When Flynn clearly only has eyes for Mathias Shaw
In the creator’s defense, Medivh was in his 20-30’s when he did the Dark Portal thingies.
I laughed at this way harder than I probably should have. 
Stukov has kids?!
Also, I think it was laready mentioned, but Leoric has kids: Albericht (“his only son” according to the Diablo 1 manual and quest text), and Aidan (his other son besides his only son, according to D3 
)
I don’t see Mephisto mentioned, but Lilith (apparently the big bad in upcoming D4) is Mephisto’s daughter (and this actually does track with D1 and D2 lore 
)
a lot of Viruses, pustules…
So much rapid aging in that dark portal business
Doesn’t change some really questionable writing decisions though. 
this isnt related much, but there is this mount in WoW, which was a horse of fire. the gag description said:
“ragnaros’ gift to the daughter he never had”
you can maybe consider that his elementals are his own sons and daughters ( like with therezane and princess theradras ) but who knows???
also, med’an was retconned not because of his mary sue-ness, but because of how insanely OP the guy was. if i were to rank him in here he would slap anyone outside god killing machines, and even they would consider him a challenge. in his… several days of training and a half broken staff, he lethally injured freaking cho’gall. imagine if he masters half of his powers. he’d casually stroll in on our raids and PEE on our heroic bosses.
Eh same thing. One of the parts of being a Mary Sue is being blatantly op with no good lore reasons to back it up.
Imagine destroy an immortal space horror with no other explanation besides “He used both energies”. I love SC but the stupid amount of power our favorite high templar used to kill The Overmind was ridiculous, Metzen can write good stuff but he is bad at writing power levels cough cough Thrall cough.
Which would make Garona even younger.
Since she was adultified, I think her age via time passed doesn’t mean much.
But the story is still messed up on multiple lvls.