There seem to be two schools of thought as to how to fight a Team Up battle:
!) A high level player uses a Damage to All spell and kills all of the enemies in the first or second round. Game over!
2) All the players of all levels take turns and blade, shield, heal and kill individual enemies. When possible, they leave the boss to the player who called the Team Up.
I've seen the people who called the Team Up react both ways. One person said, "Wow, that was cool, thanks." when all the enemies were killed at once. Another person said, "Why are you here? It takes all the fun out of it."
Personally I prefer to solo everything I can, because group dueling is tedious and the chat is often filled with dumb remarks by people who have never learned to play properly because they have always played in a group where someone else picks up their slack. I am the sort of player who finds it extremely annoying EVERY TIME when someone burns my feint with a wand blast.
That said, in the second arc you start encountering increasing numbers of cheating bosses that can't really be soloed. I hit the teamup button, play the instance, toss out a gg in chat if anyone else was at all competent, then go back to my misanthropic soloing. I don't really worry about HOW to play a teamup battle so much as how to avoid them whenever possible.
The first time I had to Team Up was the last battle of Ravenscar. I managed to solo everything up until that point, or I used crowns minions (this I did for the Malistaire final battle because I didn't trust myself or my Life wizard to be able to do it by ourselves) - but I can confirm as my Life's in Celestia, and she's alternating Celestia and Wintertusk, that the cheating bosses do either necessitate crowns minions or team ups in a lot of cases. Some of them are - well, I wouldn't say complicated, but some of them are exhausting. My hardest battle so far was my level 48 Forest Lord battle, where I had to call a crowns minion in to help. A high level one. But my personal school of thought is, if you need to Team Up, you should expect the battle to be over as quickly as possible. Because those high level wizards who are porting in to help you know from experience the faster the battle is over with, the better.
I try to solo everything too, but I'm absolutely not afraid to ask for help after the 4th or 5th time a bunch of Ravens defeat me.
That being said, if the boss is a cheating one, you usually know after the first defeat, and I usually just go to the wiki page to figure out what their cheats are so I can strategize more. But sooner or later, you can only be defeated so many times before you ask for help.
Usually I ask the person who called the Team Up what they would prefer: support or attack? Most of them prefer if I attack and end the battle in a few turns.
However, when I'm the one calling a Team Up, I like to be shielded and bladed, it makes the battle a lot more fun.
It just depends on what you prefer, so the solution here is just to make it common to ask what other people want
I realize I come off a bit smug and maybe bitter, (see my previous comment) but I feel compelled to explain my point of view in a bit more detail. To a large extent being able to solo stuff is a point of pride, in addition to avoiding annoyances that come with playing in groups. I have been away from the game since 2016, and some things have changed, the big one being the new critical system, which makes criticals occur much more frequently and do substantially more damage than they used to. BEFORE the new critical system, I could already solo everything in the entire first arc, including the final fight with Malistaire. At the moment, I am playing as a level 65 life, and the game seems almost ridiculously easy, there is not a single mainline fight I have been in I could not solo. I did use teamup to fight the four giants at the end of Wintertusk, but now kind of regret doing so; I have since come to a better understanding of the new critical mechanics and am pretty sure I could have soloed the giants. My gear is substantially better now (full waterworks and a full set of unlocked gear sockets stuffed with decent jewels), so going back to repeat it would not really be a fair test.
Yes, I occasionally lose. But I win about 99% of my common mob fights and 95% of my boss fights. When I lose I adjust my deck and tactics and try again, I literally cannot remember when the last time was I had to fight anything a third time, certainly not since at least 2016. And that includes those really tough solo battles you have to do for spells. They get tedious as I have to drag things out with a lot of healing and sometimes reshuffles, but I win them first time almost every time.
And yes, I did use teamup for waterworks. Everyone farming the place for level appropriate gear does, you simply cannot solo waterworks as a level 60 without incredible luck, even with good gear and a great pet. But waterworks is not mainline. And it is a point of pride that I managed to complete one run as a level 62 with only one level 65 teammate, it was tough and tedious and we had to go to reshuffles, but we did it.
OK, I'm bragging. My apologies for the sea of smug, you play the game the way you enjoy and that's OK by me.
I'm one of the max storm wiz who often answer to team up at the kiosk. From my point of view its hard to guess if the one who asked team up is here cuz he need help and want act in the fight or if he want to rush bosses and prefer to let me smash all before round 5. So i often aoe quick to kill minions and support the caller for the boss. Most of the time he say ty or gg but sometime i have the reduce you deck or thing like that cuz i was supposed to rush the boss for him.
And finally i have rarely "the one min i read the dialog" or a "can you let me kill the boss plz"
When you call fOr Help We Cant See For What reason you called especially for Arc 1
So Dont Hesitate To Ask What You Want For This Fight
Team up is a good opportunity to find new friends, in my perspective. I've been on both ends of it - the high level player helping and the low level player needing help. Most times I prefer to ask my friends to help me (real life friends that play :) ), and I prefer to get it done as quick as possible. As a high level player on my storm, I'll usually try to end it quickly if the person doesn't expressly say not to do it.