I noticed that Arceus-Water is sadly unrepresented on any sample teams (its even the only mon in the S or A ranks on the VR not on a sample). Similarly Ho-Oh and Miraidon are both very underrepresented considering their usage and relevance in the meta, so I want to submit one of my teams that has all three if submissions are still open https://pokepast.es/cf7a341d456b9546
CM Arceus-Water is a reliable win condition since most teams are dependent on Miraidon/Koraidon or Kyogre as their Water resists, which can all be worn down by the rest of the team or having to hard switch into Arceus-Water's attacks. Arceus-Water also has the benefit of defensively checking most physical attackers quite well.
Scarf Miraidon has better synergy with Arceus-Water than Koraidon does, and with Tera Electric can be a terrifying cleaner if the opposing team's ground types are removed. Tera Electric is also nice for the ability to guaranteed OHKO Zacian-C if it gets out of hand.
Ting Lu is the most durable Miraidon check available, which Arceus-Water needs, and sets spikes. Tera Grass is for Kyogre in emergencies since Miraidon doesn't switch in too well to Kyogre and Arceus-Water doesn't want to 1v1 CM Kyogre from behind.
Ho-Oh helps alleviate the pressure from Arceus-Water to handle all physical attackers, and is a great wallbreaker with substitute. The 248/16 physical bulk is enough to always survive +1 Wild Charge from Zacian-C and +2 Photon Geyser from defensive dd Necrozma-DM at full health while still taking special attacks well. The speed is for Gliscor so Ho-Oh can sub before being hit by toxic, with the rest of the EVs put into atk.
Zacian-C gives the team insurance against EKiller, another option for revenge killing, and another potential win condition or breaker that capitalizes really well on the pressure sub Ho-Oh can apply. Zacian's fairy typing is also helpful against Scale Shot Koraidon without having to invest Tera.
Giratina-O is a nice backup check to a lot of threats that can also phase out dangerous sweepers. Defog is a necessary evil for this team to not lose to Toxic Spikes. Poltergeist is surprisingly difficult for most teams to switch into, especially with Ho-Oh and Zacian-C already breaking most physically defensive cores. Thunder Wave support helps Ho-Oh and Arceus-Water both fulfill their roles more effectively or potentially win if one of their checks gets statused.
Maintaining momentum is very important as its not easy to play from behind against threats like Kyogre, Zacian-C, and Miraidon. However, this team can be very difficult to stop once it gets ahead. The gameplan is a pretty straightforward offensive one of "hit everything as hard as possible", but some intelligent switching is required to position properly with Arceus-Water and Ho-Oh since they're not particularly fast or immediately threatening to most teams.
CM Arceus-Water is a reliable win condition since most teams are dependent on Miraidon/Koraidon or Kyogre as their Water resists, which can all be worn down by the rest of the team or having to hard switch into Arceus-Water's attacks. Arceus-Water also has the benefit of defensively checking most physical attackers quite well.
Scarf Miraidon has better synergy with Arceus-Water than Koraidon does, and with Tera Electric can be a terrifying cleaner if the opposing team's ground types are removed. Tera Electric is also nice for the ability to guaranteed OHKO Zacian-C if it gets out of hand.
Ting Lu is the most durable Miraidon check available, which Arceus-Water needs, and sets spikes. Tera Grass is for Kyogre in emergencies since Miraidon doesn't switch in too well to Kyogre and Arceus-Water doesn't want to 1v1 CM Kyogre from behind.
Ho-Oh helps alleviate the pressure from Arceus-Water to handle all physical attackers, and is a great wallbreaker with substitute. The 248/16 physical bulk is enough to always survive +1 Wild Charge from Zacian-C and +2 Photon Geyser from defensive dd Necrozma-DM at full health while still taking special attacks well. The speed is for Gliscor so Ho-Oh can sub before being hit by toxic, with the rest of the EVs put into atk.
Zacian-C gives the team insurance against EKiller, another option for revenge killing, and another potential win condition or breaker that capitalizes really well on the pressure sub Ho-Oh can apply. Zacian's fairy typing is also helpful against Scale Shot Koraidon without having to invest Tera.
Giratina-O is a nice backup check to a lot of threats that can also phase out dangerous sweepers. Defog is a necessary evil for this team to not lose to Toxic Spikes. Poltergeist is surprisingly difficult for most teams to switch into, especially with Ho-Oh and Zacian-C already breaking most physically defensive cores. Thunder Wave support helps Ho-Oh and Arceus-Water both fulfill their roles more effectively or potentially win if one of their checks gets statused.
Maintaining momentum is very important as its not easy to play from behind against threats like Kyogre, Zacian-C, and Miraidon. However, this team can be very difficult to stop once it gets ahead. The gameplan is a pretty straightforward offensive one of "hit everything as hard as possible", but some intelligent switching is required to position properly with Arceus-Water and Ho-Oh since they're not particularly fast or immediately threatening to most teams.