Shadow Ho-Oh

Shadow Ho-Oh gains improvements in PvE thanks to the ATK buff from being a Shadow Pokemon. It has received its signature move, Sacred Fire. However, Sacred Fire's parameters aren't much better than Fire Blast's, making Shadow Ho-Oh an inferior Fire attacking choice compared to Shadow Moltres, Shadow Entei, Shadow Charizard, and Reshiram. Additionally, Sacred Fire is gated behind an Elite TM for Shadow Ho-Oh. Nonetheless, Shadow Ho-Oh is a very respectable Flying attacker thanks to Brave Bird's power, further improved if you are lucky enough to roll Hidden Power Flying. As Fire and Flying have some overlaps in coverage, Shadow Ho-Oh can pair Incinerate and Brave Bird together to dominate Grass- and Bug-type raid bosses.

For players who paid for GO Tour: Johto, they have access to Apex Shadow Ho-Oh. This variant of Ho-Oh naturally comes with Sacred Fire+, a stronger version of Sacred Fire. With this move, Apex Shadow Ho-Oh becomes a very powerful Fire attacker, with an overall performance rivaling that of Shadow Moltres and Shadow Entei. Do not purify Apex Shadow Ho-Oh if you care about raid dps, as it loses a considerable amount of dps despite receiving Sacred Fire++.

Best PvE Offensive Moveset

• Incinerate is the best fast move available due to STAB. 

• Extrasensory is better for effectiveness vs. Fighting-types specifically.

• Steel Wing is mostly useless.

• Hidden Power is only viable if it is Flying type. Otherwise, Incinerate or even Extrasensory are better options.

• Brave Bird is the best charge move available, and benefits from STAB.

• Sacred Fire* is Ho-Oh's signature move, and makes it a respectable Fire attacker. However, it requires an Elite TM.

• Sacred Fire+* is exclusive to Apex Shadow Ho-Oh and it's objectively stronger than its base version. However, basic Sacred Fire is still great.

• Fire Blast is much slower and doesn't perform as well, except against Ice or Steel-types. 

• Solar Beam is the charged move of choice against Water, Ground, and Rock-type Pokemon, but lacks STAB. 

• Earthquake is a bit of an awkward move on attack for Ho-oh and doesn't do much for it.

Incinerate is Ho-Oh's only viable fast move option due to its high STAB damage and energy generation, though it is quite cumbersome being a 5 turn fast move. Extrasensory and Steel Wing are both inferior choices by a considerable margin, though they don't suffer nearly as much from the slow animation that Incinerate has. Hidden Power is not a great attack in PVP, but it can have some niche utility on Ho-Oh if given the proper typing.

Brave Bird demands quite a bit of energy, but is the cheapest charge move available to Ho-Oh. While its self-debuff makes it somewhat risky, its high STAB damage makes it considerably threatening if unshielded. Sacred Fire is a very powerful STAB move with a 50% Attack debuff chance, and burns down Steel-type targets Also worth noting, it has the same power in pvp as Sacred Fire+, so a non-Apex Ho-oh is just as good here. Earthquake provides coverage against Rock types and certain targets such as Zekrom. Solar Beam and Fire Blast are among the most expensive charge moves in the game energy-wise, but the former provides coverage against Water and Rock Pokemon that Ho-Oh can struggle against, while the latter is best avoided because it is completely outclassed by Sacred Fire.

Sacred Fire+ is functionally identical to Sacred Fire in PvP