#1 He can stay and succeed Ramos as Real's new captain for years to come

With three years left on his existing deal, Varane finds himself on the cusp of his peak career years. It's very idealistic to expect players to remain loyal when lucrative offers from abroad start flooding in, although the Frenchman hasn't yet had his head turned and at 26, there's plenty of scope for a more significant role at Real in future.
As previously mentioned, Ramos is already arguably on the decline and most of their core find themselves the wrong side of 30. Marcelo, Luka Modric, Karim Benzema, Toni Kroos and Gareth Bale (both 29) are all top players who need replacing with long-term investment at some stage.
Varane turned 26 last month and it's very romantic to suggest he'd be open to committing his future to Madrid for the remainder of his professional career. The volatile market in recent seasons has proven top defenders command a premium price - see Virgil van Dijk - and he'd probably be the first to break a nine-figure transfer fee if available.
However, with performance-related bonuses, assurances and the promise of being made their new captain to succeed Ramos, it makes for an interesting proposition. He already leads by example with his defensive displays, although not in the same way Ramos does, but he commands respect from peers and opponents alike.
Admittedly, he hasn't always felt as appreciated as his talent deserves but it comes with the territory: you don't know what you have until it's gone. Ultimately, this is a man they signed from Ligue 2 side RC Lens for £9m eight years ago - if they convince him to move to greener pastures at some stage when he's blossoming into his prime, they'd be making a very expensive mistake.