Whenever you capture a shadow Pokémon in Pokémon Go, there’s a small debate if you should purify it or not. A shadow Pokémon has 20% more attack power than its regular form, but it also lowers its defenses by 20%. Also, shadow Pokémon know the default charged move frustration, and they can only remove it during specific times in Pokémon Go. Beyond these time frames, they’re stuck knowing frustration. By purifying a shadow Pokémon, they return to their standard form, their attack and defense power are normal, and they can learn charged moves. Do you want to purify shadow Ho-Oh?
For most shadow Pokémon, it all comes down to if you can remove frustration. Niantic has gotten better about having more events that make it so players can remove a shadow Pokémon’s frustration. Shadow Ho-Oh is the same way. However, because it is a legendary Pokémon, obtaining its shadow version is much more difficult. The only way you can do that is by defeating Giovanni, and the shadow legendary Pokémon he captures rotates out pretty often. It also comes down to obtaining a Super Rocket Radar, the only way to locate Giovanni.
Due to the limited amount of opportunities you have to encounter Giovanni and catch his shadow legendary Pokémon, almost any shadow legendary you capture should never be purified. It’s better to keep them in their shadow versions, and the same goes for shadow Ho-Oh. When you compare it to its original version, the two are nearly identical, with the original version of Ho-Oh being slightly better. Shadow Ho-Oh is a risky choice, but when using it in PvP situations, we recommend utilizing it as the final Pokémon that you use. It has enough defense to make it difficult to defeat, and the increased attack power makes it a threat to any trainer.
When you have the chance to capture shadow Ho-Oh, keep it the way it is. We don’t know the next opportunity you have to capture it again. The standard version of Ho-Oh shows up often enough to make purifying shadow Ho-Oh a waste of time.