Ho-Oh useful?
With steel wing and solorbeam a great counter for regice? Resists its ice type moves and focus blast, has bulk to also be an anchor to prevent fainting out the raid battle.
Answers
Pokebattler suggests it is the 7th best counter for Regice (Entei, Moltres, Mewtwo, Machamp, Heracross, and Hariyama come before it respectively) Mewtwo and Heracross aside, you’re much better off powering up one or two of any of these Pokémon, some more than others, before powering up Ho-Oh. This of course assumes you don’t have a surplus of Ho-oh/Rare Candies and dust.
Disagree with the last part. Agree that Ho-Oh isn't super useful.
Fire Blast with STAB has 175 Power (base damage) before weather, SE/NE, etc. Solar Beam without STAB has 180 Power. The two are almost equal, and both are buffed by clear weather.
The main driver for Ho-Oh's usefulness with Solar Beam is when you need to hit something with Grass and that something is very effective against Grass. Not a long list, sadly.
I've been pondering use of a SW/SoB Ho-Oh as an anchor against Tyranitar. As long as the Ttar isn't packing Stone Edge (2/3 chance it isn't), Ho-Oh resists fire and steel, and both Steel and Grass are SE (1x) against Ttar. Need to see if something else is more effective for less dust (clearly Machamp, but he shines against SE and the dark moves, but struggles against Fire and Steel - possibly Blaziken, who is good against everything but rock, etc.)
While his moves are a little wonky, Ho-Oh does have that obscene CP, and the accompanying stats. An example. My powered up Entei is level 31 and has CP 2889. The weather buffed Ho-Oh I caught last night is level 25 and has CP 2727 (average for a raid mon). Even hampered by a non-ideal moveset, I can see Ho-Oh being stronger than Entei for a comparable investment in dust. (Yes, this partly relies on the fact that Entei didn't get weather buffing, but that's the reality of the game right now).
So, while I don't see a clear useful niche for Ho-Oh now, I think there's a distinct possibility that it's not as irrelevant in the meta as people are making it out to be. Or that if it is, Niantic will de-nerf it to bring it up to speed (if that's the case, just sit on the Ho-Ohs you have, and wait.)