I don't get the hate for the New Varus Lore
Character Old Varus - straight forward old archetype of man torn between family and duty, lost family, and is now out for revenge (plus 1 for corruption via the mcguffin he was meant to protect)
New Varus - ancient being whose kind once laid waste to runeterra, lost war and was sealed, and now is back and wants vengeance on humanity for sealing him and taking out his kind.
Power Source Old Varus - already a deadly archer in his own right, gets a mysterious dark power that has slowly been eating at his being since he made his choice.
New Varus - already a deadly archer in his own right on top of being from a race of very powerful beings (plus whatever bonuses and weakness from having a vessel of flesh and bone now instead of whatever darkin normally were)
Sexual Alignment Old Varus - once a happy family man with his wife and child
New Varus - no signs of which way he swings, let alone we have no idea how darkin came into being, let alone how they reproduce and stuff like that.
Animations and Lines. If anything Riot will eventually get around to him and give him a new model but for now we just have to wait and hope get at least new lines within a month or 2. Let us remember they are constantly working on multiple projects, and other characters with bigger inconsistencies with newer lore still have yet to be touched (i.e. Orianna).
At the end of the day we should of seen new Varus lore coming when Kayn's stuff came out. Everyone already figured Varus was now connected to the Darkin story in some way, and Riot just chose to go in and make it big. Varus is still deadly archer driven by vengance and Varus even still has a "family" given that with his color story currently puts him in Shurima looking around Xerath's Tomb for any clue about his "Sister".