Possible idea, each boss tries to or has kidnaps the Player if they somehow separate them from their vessels
It would be their most effective strategy, in all honesty!
Especially since the Player is the one pulling the vessels around and guiding them through the battlefield with grace and ease. Separating them would give the enemy a chance to get some hits on as well as sever the connection that the group has with the Player, even if it's just temporary.
Each one would possibly incapacitate the Player in some form of way.
The Mag Bandit would probably keep them in one of his hands while he swings with a weapon using his other hand. (Both encounters)
Church and Jorge would each swap and toss the Player between them while each takes turns pulverizing their precious vessels. (All encounters)
The Sheriff may entrap them in one of those assembly claws to keep them away from their vessels and incapacitate them.
Burger Gil would probably trap them in a pot or the oven and the vessels would have to deal with Gil before rescuing their Player.
Jeb would probably not actually harm them but would focus some of his keystone energy into suppressing them or keeping them close to the rafters via floating.
Tricky would 100% steal them away from the group on the rigged platforms (aka Madness Time) and keep them up there with him while the vessels fight for their lives.
Crackpot would have them be kidnapped by fanatics during his levels and will only be freed after the boss battle with him is finished.
The Ghoul would probably stun the Player majorly. Even if they don't take any damage, it wouldn't feel good to get stomped on by a motorized bug.
The Hive may tangle them up in wires or stun them with electricity. Again, even if they don't take damage, it probably won't feel good to get zapped.
The Blackguard would have his allies probably hold onto Player or drag them around forcibly and keep their hands pinned throughout the fight.
Gestalt would only be able to actually get Player during the final battle, in which he also holds them in one of his hands tightly while the vessels scramble to do something to free them. Especially since this is the final encounter and Gestalt is now big enough to eat you whole. (Only final battle)
Phobos would probably forcibly keep the Player close to him or keep them wrapped up in energy binds as he attacks the vessels to 'get rid of them so nothing stands between you and Phobos'.
Hank would probably keep talking to the Player about joining him and pleading with them (aka manipulating their emotions) so that they can finish the mission together. The Player stays out of the fight until Sanford and Deimos begin to lose, to which they side with them and defeat Hank. Probably giving him a sad look and telling him that they were so disappointed in him.
