Miraidon ex (Post-Rotation)

Strategy: Tapu Koko ex is an early game attacker like Raikou V once was. Iron Hands ex is basically the main attacker as usual since Amp You Very Much is too good still. Iron Bundle helps force your opponent to bring up a Pokémon they don't want. Bloodmoon Ursaluna ex returns and helps as an endgame attacker and with Defiance Band can do 270. Pikachu ex as usual activates Area Zero Underdepths. Magnezone ex helps deal with

Strategy: Tapu Koko ex is an early game attacker like Raikou V once was. Iron Hands ex is basically the main attacker as usual since Amp You Very Much is too good still. Iron Bundle helps force your opponent to bring up a Pokémon they don't want. Bloodmoon Ursaluna ex returns and helps as an endgame attacker and with Defiance Band can do 270. Pikachu ex as usual activates Area Zero Underdepths. Magnezone ex helps deal with Farigiraf ex from Wall Decks due to that countering this deck. Additionally, if you go up against a Raging Bolt and they have a ton of energy in play or any other deck like Hydrapple ex, Energy Crush can nuke them for doing so. Miraidon ex's Tandem Unit helps bring your Lightnining Pokémon into play as usual and can even be used as an additional attacker sometimes. Fezandipiti ex helps draw cards after a Pokémon was knocked out, Mew ex helps when you have a small hand, and Latias ex gives all the Pokémon besides Magnezone ex and Magneton free retreat. Rescue Board helps just in case Latias ex gets prized and Switch helps if either of those are prized or if Magnezone ex or any other Pokémon is trapped in the active. Also, yes Secret Box the typical ACE SPEC for Miraidon has been replaced with Prime Catcher as it's helped me much more in testing compared to Secret Box. I'd also recommend going second with this deck as usual Miraidon decks.

Summary: Since rotation dropped a nuke onto Miraidon ex, Tapu Koko ex is the new Raikou V from Walgreens which isn't that good but is still a replacement. Incase the Magnetons can't blow up, you can evolve it into Magnezone ex which the first attack potentially helps with Raging Bolt ex and the second attack is the same as Miraidon's but instead does 30 damage to itself(recoil). Magnezone ex also helps with Farigiraf ex since it isn't a basic Pokémon. Anyways, feel free to change anything or comment any suggestions.

Matchups:

Dragapult ex: Pretty solid matchup just like in Traumatic Evolutions, target the Dreepy's and Drakloak's earlier on, try to take out Fezandipiti ex if it's in play as well. (50/50 Matchup)

Gardevoir ex: Amp you very much goes brrrr or on other words, use Iron Hand ex's Amp you Very Much to take out those powerful basic Pokémon. (In Miraidon's Favor so about a  30/70 matchup)

Archalduon ex: Can wall Miraidon pretty badly, though it's possible to win still. A way to win would to take out the Duraludon's earlier on, get rid of their liabilities like Squawk if it's the poison variant, if it's Hop's Zacian the only way to one shot it would be with Bloodmoon Ursaluna ex or using Mew ex to Brave Slash them. (About a 75/25 matchup) ((25 is Miraidon))

N's Zoroark ex: A balanced yet fun matchup, Amp you Very Much their benched Pokémon to take two prizes and prevent Zoroark ex from attacking and also take out Zorua's early on. (About a 50/50 matchup)

Raging Bolt ex: One of Miraidon's biggest weaknesses, take out Teal Mask Ogerpon ex's along with Fez. Also, try and Amp you Very Much their single prizers. Energy Crush may help in this matchup as well. (About a 75/25 odds wise for this matchup, Miraidon's is the 15)

Charizard ex: Try to knockout the Charmander's earlier on, if they have any Pidgeot ex's in play take those out, along with Fez. You could also force them to take a prize by sacrificing Magneton to then use Defiance Band on Bloodmoon Ursaluna to hopefully knock out Zard. (Around a 85/15 matchup)

Gholdengo ex: Pretty fun matchup and can go either way, I'd recommend to take out the Gimmighoul's earlier on, take out Munkidori's, if they're playing the Dudunsparce Build, try and Amp you Very Much the Dunsparces. If it's the variant that plays Pult, well you're basically doomed unless you target the Dreepy's and Drakloak's. (Normal Build w/o Pult: 45/55, Dudunsparce Build: 55/45, Dragapult Build: 60/40).

Wall Deck: Use Magnezone ex up to counter Farigiraf ex. The other wall mons gets countered pretty easily, though, if they have the disgusting, vile, Mimikyu then use Boss's Orders to play around it. (Matchup is about a 45/55)

Roaring Moon ex: Pretty much in your favor as Roaring Moon was also bombed but Miraidon has some new tools like Tapu Koko ex. (Matchup is about a 40/60)

Miraidon ex: Whoever gets the first two prizes pretty much wins like typical Miraidon mirror matches. (Literally a 50/50)

Terabox: Pretty interesting matchup, Cornerstone gets counter by Koko, Hands, and Magnezone, Terapagos gets knocked out pretty easily, Wellsping is just a free to prizes. (Matchup is about a 45/55)

Feraligatr: Quite literally weak to your whole deck, though, Mimikyu is the main threat to Miraidon so just use Boss's Orders to get around it. (About at 35/65 matchup)

Budew Froslass: Amp you Very Much their Pokémon and avoid putting too many Pokémon with abilities into play. (About a 45/55 matchup)

Koraidon ex (The one I made because why not): This is quite literally a useless matchup as you will probably never face this deck but if you do, knock out Koraidon ex as soon as possible and take out the one prizers if possible. (About a 60/40 for the matchup)

Edits:

Edit #1: Cut out a copy of Professor's Research for a third Boss's Order. This change happened as I did some testing and there were times I lost because I didn't have a third Boss's Order.

Edit #2: I did way more testing and reworked this deck a bit. I dropped it down to 2 Professor's Research, made it 4 Arven's, removed a Grass and Metal Energy, removed a Pikachu ex, removed a copy of Area Zero Underdepths(I may regret this one), added in a Gravity Mountain to help with stage two decks, added in a defiance band also to help against stage two decks, Iono was added in for disruption, Iono's Wattrel and Iono's Kilowattrel are here for draw support, and sadly dropped the energy count of Lightning from 14 to 12(I really don't think this is a good idea but uh it needs to happen in order for these cards to help Miraidon).

Edit #3: Did more testing and I did in fact regret changing the energy count. Defiance band didn't help much, Gravity Mountain works for countering the stage Two's only downside is it affects Magnezone ex. Iono's Kilowatteral helped work with Magneton by discarding cards and keeping my hand a decent size. Iono's Kilowatteral helped fight back against Mimikyu from the Wall Decks and helped against Farigiraf ex as well. I removed Iono, removed Defiance Band. What replaced them was 2 Lightnining Energy so it goes back to 14.

Edit #4: In testing Iono's Kilowattrel didn't help much. So I removed Iono's Wattrel and Kilowattrel and they were replaced with Defiance Band and Super Rod. Magnezone ex helps take care of Farigiraf ex in wall decks. I'm thinking of going back to 2 Area Zero Underdepths since Defiance Band is back in.

Edit #5: Removed defiance band, super rod, and rescue board. The cards in testing did not help much at all. Their replacements are as follows: Reedemable Ticket, A 2nd Area Zero Underdepths.

Edit #6: Removed Gravity Mountain, removed a copy of Arven, Redeemable Ticket, and Crispin. Crispin didn't help much at all, Redeemable Ticket may return but for now is removed. Rare candy was added to help get into play much quicker. Rescue Board returned as Latias ex gets prized often from my experience, Defiance Band came back because it's much better than mountain. Updated Tapu Koko ex to the Journey Together one.

Edit #6: Iono's Kilowattrel has not helped me much at all, therefore, it's been cut and has been replaced with 4th Arven, and a 3rd Ultra Ball.

Edit #7: Removed both Professor's Research as they didn't help much at all. In addition to these removals, I added in a 2nd Squawkabilly ex as it seems pretty fun, also added back Super Rod because Night Stretcher isn't enough.

Edit #8: Removed the Rare Candy, 2nd Squawkabilly ex, and Secret Box. They were replaced with 2 Professor's Research(I regret removing this), and Prime Catcher(Miraidon's older Ace Spec build before replaced by Secret Box  during Stellar Crown).

Edit #9: Removed the energies for Pikachu, removed a Professor's Research, in addition, 2nd squawk returned as it helped with overall consistenty, Pikachu's attack basically never came into play so along with that Bloodmoon Ursaluna and Bundle returned as well.

Edit #10: Removed Professor's Research for a 4th Boss's Orders. I've seen many other Miraidon players running 4 copies of Boss I tried it out and it's way better then having 3. So since Professor's Research was rarely used it has been cut for a 4th Boss's Orders.

Edit #11: As much as I enjoyed 2 Squawk's in the deck, I unfortunately had to remove 1 of the 2. It was great and all but had to be removed for a Counter Catcher as it's proven to be more useful since you'll likely be behind on prizes most of the time. Also, I have decided to release the Lillie's Clefairy ex with Miraidon build as its own deck. Additionally, Tapu Koko ex kind of feels odd so I'm not debating whether to remove it or not.

Extras:

A link to the other Miraidon ex build if you want to check it out: https://pokemoncard.io/deck/miraidon-ex-with-lillie-s-clefairy-ex-journey-together-123191

Link to my 3rd Miraidon Build: https://pokemoncard.io/deck/miraidon-ex-joltik-box-journey-together-123874