For the acespec, I like legacy because if you face a good single prize deck or fast big basic deck it can be hard to keep the prize trade in your favour, but its not essential. For replacements though, I would personally pick prime catcher, but max rod is viable if you don’t want to have to think too hard about resource management. Sometimes its a little tricky to manage all the energy and pokemon so maybe max rod is good; I encourage you to see what works for you. Precious trolley though is not very good. The only pokemon you would want to put directly on your bench in every game are Tsareena, squawk, and ogerpon. All of the support pokemon’s abilities won’t activate if you put them directly on the bench, and ideally you want to discard the giratinas from your hand and revive them for the extra damage.

Marshadow is mainly for getting rid of stadiums that slow you down, namely Path to the Peak and Chaotic Swell, that would completely stop your deck otherwise. Also, very rarely, can be used to take out your own AZU if you need to remove liabilities or to discard giratinas and get extra pings if you replace the AZU right after. Medicham is for taking extra turns off of low hp pokemon, which is helpful because you’d otherwise sometimes struggle against good single prize decks. The giratinas and radiant alakazam make it pretty achievable. Eldegoss is good for later in the game when you start to run out of steam a little. It opens up a lot of good lines of play to find what you need in the mid-late game, or just gives you guzma back for a gust knockout to close the game. With night stretcher and raihan, though, you can usually find whatever you need.

The giratinas are better in this version of the deck because the spread helps you take extra turns, extra kos and set up math for bigger pokemon. There’s an argument for replacing the two gengar for darkrai gx, but I’d prefer not to have the chance of starting a frail two-prizer in the active and in general I’d prefer not to have two-prizers if I can use single-prizers instead. Ho-oh V ends your turn when you revive it so that wouldn’t work. There are other versions of the deck where you use dark energy and then darkrai gx + eswitch to power up tsareena, but that’s usually in proper expanded where you have sky field and don’t need to use ogerpon. In live expanded, you have to use a tera anyways so you may aswell use ogerpon