Hrm...for Giratina, I say the LA one is pretty nice. It's actually quicker than other Giratinas (Most need 3 for their first attack, except DB Giratina, but it's horrible. Trust me, there are other DB Pokemon, and they always get owned.), and it's second attack is actually decent and good to use after Giratina X's attack. For the second Giratina, I'd use the Let Loose one. It not only disrupts your opponent, but if you have a bulky hand and a slim deck, the Let Loose will help. Besides, why use Dark Wing Flaps on that Pt. Giratina if you can use Earth Power on Let Loose Giratina?
I use the Promo Dusknoir, because that's all I have, except for the Darkness Mist one. Personally, if your strategy is to spread damage, Darkness Mist Noir is useful, but so is Promo. Now Dark Palm one is often used and is very good as well as the Shadow Command. I think all the Dusknoir are good, nothing will disrupt the play. I can't really say, I have only used the Promo Dusknoir. All I have to say about it is that it has healing powers with Reaper Pulse, and can easily make 2 KOs. Especially if you warm it up with Giratina X, or the other way around.
Quit. For real this time lol. Moved to Pokebeach as Tyaniking a long time ago. The only thing keeping me here was the games corner and the really fun RPGs, but those are out, so I started going to the TCG section, but that's pretty much dead. I'm trying to get into the video games, but most of my time is devoted to the TCG, so IDK how it's gonna go. If I get back into the games, I'll probably come back. Besides, most of the other TCG crew moved to Pokebeach as well. Any of my groups or games may be closed or they may be remade by anyone who wants to. I give full permission. I'm sorry I have to leave, but that's just life.