Finished!!!!

[Lord Windos]

While I like the idea of a friendship evo of Chainite, I think the way you executed is off, though in no fault of your own, truth be told. The reason are that, as Iron mention, we already have a angel Pokémon (Dunsereph), and that another Pokémon (The Luxi line) has Regenorator as a Hidden Ability (When it will get it, on the other hand, is another matter entirely...). I say emphasize the more Etherial, spiritual aspects of the Linkite line, and find an ability that more closely matches its Guardian nature. The first ability I could think of would be Magic Bounce, as that would fit the role of protecting team mates, but Magic Guard fits as well, as it would allow it to do its job relatively unhindered. Levitate is also an option as well, if you just want a good ability for the 'mon.

I'd say that you could also change its type to Ghost-Fairy, as I believe its fits the theme of 'love redeems' better than dragon typing, and it differientiates it even more from Dunsereph. Good HAs could be either Friend Guard or Symbosis, as those abilities can not only give it a niche that no other Pokémon has at the moment, but it would also give more flavor to the Pokémon itself. Seraphite, Guardian Supreme has a catchy ring to it, no? Its Mega Ability could be either Unaware (If a sweeper attempts to set up, it can Mega Evolve to attempt to shut down) or Stamina (Every time something try to knock it down, if only gets tougher for their effort). Giving it either Haze and Recover on top of that would be a nice addition as well.