Tested this out multiple times with both teammates and between my own two devices.
- Attacker can have a roster with as many dragons as they want
- Follower only has one dragon in active roster (in our instance it was a level 1 Ember for xp farming)
- Attacker goes through the attack as usual, then swaps out or dies
- Follower comes in with their ember, swaps out or dies.
- Instead of returning to the dragon select screen for lead attacker, the attack ends with a dragon defeated screen (or maybe a victory screen if you complete over 70%).
At first I thought it was my own game screwing up so I restarted, restarted phone, all that jazz. But me and a teammate (and then after that my own two devices) were able to successfully recreate this while also having 0 issues if the follower had multiple dragons in the roster.