>>58069502Dialga is way too slow. Ho-Oh starts off with 80 daamage, that's very respectable and enough to soften a target up before Rayquaza nukes. Dialga takes 2 turns before you can start charging, and when it does charge it only does 60 damage total before clocking out. Plus it doesn't have access to heals from Irida.
>>58069553Rayquaza attacks the bench too, so unless you have nobody else out then I still have a chance of winning. Chances are, you have other more valuable targets in the back for Rayquaza to tackle and I'll just outheal/Lima up if I get too low.
Though you can certainly tank it if it's your ONLY Pokemon in play, but there's rarely a time where that's the case. Well, I lie, there are tons of times where that's the case but only when I'm playing Oricorio and my opponent has no EX mon.