I'd urge everyone that is on the fence about Fury to listen to the Joe Rogan Podcast where he talks about his addiction, weight gain and motivation. It was recorded on the run up to the Wilder fight, so there's some good insight in to his training regime which will surprise a lot of people too.
Before I heard that I thought he was an arrogant arse who deserved to be sparked out but he came across very articulate and I fully understood his reasons for doing what he did/does. It's probably the most honest interview I've heard from a top sports person that isn't ego-driven... in fact, it's incredibly humbling and he certainly has a lot of humility.
tl:dr... he achieved what he wanted (by beating Vladimir) so then lost the desire to fight, gained weight, got hooked on coke and spent his money.
He did a good interview for the breakfast club too