Genuinely one of the worst experiences I've had with this game, I think I'm gonna take a few weeks off from Bloons. Maybe come back for an actually good boss event but that's it.
There's a whole list of reasons I hated this and ways to make it better, but TLDR it's too many repetitive tasks, should've been more challenges you only do once.
So due in part to the new boss challenge I decided to try out how well ROD worked on diamond back and its summons. Now as you would expect, the ray does go right though diamond back, but the head stops the actual damage. Resulting in Bloons behind it looking invincible to the ray.
Obviously this is all expected, but I just think it's funny how they don't have the ray stop at the head (I understand that's probably a lot of work and a re-write of ROD's laser)
Also I know this has been mentioned, but don't use ROD for the diamond Bloons. It attacks really slowly for some fuckass reason and it won't pop them in time