Giratina-Altered returns to Raids, this time with a possible Shiny form. While this Giratina is still useless for PvE, it is arguably the single best Pokemon for PvP. For people who don't care about PvP, doing Giratina-A raids should still be a priority, as this Giratina shares Candy with Giratina-Origin, who is still the best Ghost-type attacker in the game.
Outside of Wind, Giratina-A is a fairly easy trio.
Minimum viable levels assume Best Friends, Windy Weather, no Dodging.
Italics indicate a Legacy move.
Ancient Power can sting a bit against the Flying Dragons, but Windy-boosted Dragon-type DPS is so high that, even accounting for a relobby time of ~20 seconds, you should have a comfortable 20-40 seconds of leeway.
Shadow Sneak is mostly the same story as Ancient Power: even with Giratina spamming back-to-back Shadow Sneaks, Dragons have such high DPS in Wind that you should be well ahead of the timer during the entire fight.
Dragon Claw is a different story from Ancient Power and Shadow Sneak. Even with Giratina's low 187 Base Attack, tanking consecutive Windy-boosted Dragon Claws is not pleasant. Death counts are high enough against Dragon Claw that you may need to relobby twice, which is a lot of time lost.
If you can dodge Dragon Claws, avoiding a 2nd relobby will give you much more leeway on the 300-second timer.
Minimum viable levels assume Best Friends, no Weather, no Dodging.
Italics indicate a Legacy move.
Trioing Giratina is much easier than duoing it, even without Wind. Pokemon other than the Big 6 Dragons become viable at relatively low levels, making the Giratina trio much more accessible.
Shadow Sneak and Ancient Power Giratina are honestly so easy to trio that there's not much to say: as long as your Pokemon are at the specified minimum levels with the specified movesets, you should win with plenty of time to spare.
Dragon Claw is still significantly harder than the other two Giratina sets, even without Wind. Relobbying twice is still a concern, especially with underleveled Dragons; however, with 3 people, the fight's DPS requirement is much more relaxed, and even if you need to relobby twice, you should still win with a lot of time remaining on the clock.