Honestly i would stick with Talonflame since it's an excellent partner for Xerneas (and in general it offers a guaranteed Tailwind for your team). The main reason being priority LO Brave Bird for some damage on opposing boosted Xerneas (we are still talking about a 2HKO on a standard 4HP Xerneas) or to finish off anything you put in KO range with your boosted Dazzling Gleam / Moonblast, which is more important than people think; then you have priority Tailwind to match any opposing Tailwind in the blink of an eye; another great move on Talonflame is Quick Guard, since M-Ray Extreme Speed and Scizor Bullet Punch are really strong, you have a mean to stop those attacks (actually, you make Scizor useless in front of your Xerneas), not to talk about opposing Talonflame Brave Bird targeting your Xerneas, which you can stop. Thanks to Quick Guard you also completely shut down Prankster TWave, Quash, Encore and many other things (Whimsicott, Thundy and Liepard). Then you also have Flare Blitz which is another option to OHKO opposing Ferrothorn, when you can't switch in your P-Don safely or when it's gone.
PS: try Focus Sash on Thundurus :D
PS: try Focus Sash on Thundurus :D
