Dynamax Adventures | Bulbagarden

As I said before DA are great. It's fast paced, engaging and very rewarding because of the shinies (even if I've yet to find one) and the legendaries. I prefer sitting through battles rather than through an extremely unfair minigame (looking at you Ultra Warp Ride). And unlike that terrible feature you at least have a way to control what you want.

Tbf, Ultra Warp Ride had relatively easy Shinies as well.

Still, while I actually liked the wormhole minigame, it was way too random and easy to mess up. Dynamax Adventures are clearly trying to address some of those problems. Like, how even if you lose against a DA Legendary, you get to record 3 up to paths so that you can try again for that one as soon as you want instead of having to hope you get the right wormhole to spawn again and having to hope you don't screw up and hit too many electric orbs.

Also, DA has just 8 version-exclusive pairs (Ho-Oh/Lugia, Latios/Latias, Groudon/Kyogre, Dialga/Palkia, Tornadus/Thundurus, Reshiram/Zekrom, Xerneas/Yveltal, and Solgaleo/Lunala) whereas UWR had 11 (Raikou/Entei, Ho-Oh/Lugia, Latios/Latias, Groudon/Kyogre, Dialga/Palkia, Heatran/Regigigas, Tornadus/Thundurus, Reshiram/Zekrom, Xerneas/Yveltal, Buzzwole/Pheromosa, and Kartana/Celesteela); plus with DA, everyone can access Suicune, Rayquaza, Giratina, Landorus, and Kyurem without needing both of their corresponding trio members. So that's pretty nice.

By the way, does anyone knows how to join someone else's adventure? Both Bulbapedia and Serebii have zero information about it.

I think you've got to use Link Codes. See this picture:

There's that text at the bottom saying to press + to set or enter a Link Code.