I reached Legend for the 2nd time on Hearthstone… because I wanted to know if I could repeat it without a non-brainless deck like Secret Paladin and I did it with a the brainless Dragon Warrior deck.
I don't think I'd do it again though, because the grind is just unfun. The most important thing is to 'feel« the meta of the day you are playing and change decks accordingly and of course, have a unhealthy dose of luck.
Everybody is talking about Legion and if I had infinite time I'd play it but WoW is like a jealous girlfriend. You either play only it or playing everything else.