repeated :)

Sorry what?

Err... IMHO, the next yellow summon you should aim for is one that complements your roster of ninjas.
Esp now with the Kage treasures out, you'll have new ninjas with different chases out.
See which summons can complement your chases to extend your combo and you'll have your winner.
(eg. if you get Rhino but have no use for it in your lineup then that defeats it's purpose don't you agree?)

It wouldn't be a waste if Belerephon was a person who changes their team/lineup often. I get what you're saying, and yes, I agree, your statement would be correct if they don't change lineup often, and didn't have the summon needed for their combo.

I think you should either get Lightning Tiger King or Rhino. There are lot of ninja that chase repulse in the Kage treasures, so as your roster increases, you'll find these guys increasingly useful.

I have flood dragon, and I don't really find myself using him that much, just because not a lot of ninja in the current meta chase high float.

I believe you may have mis-understood me there.
I mentioned that his next yellow summon should complement his line-up, which means whichever line-up he desires but it depends heavily on his current roster.
You can change your line-up as often as you'd like but if the summon doesn't really match your chases then it's of not much use.
(eg. I don't use Giant Katsuyu much as I don't have a lot of strong ninjas which chase low float, etc)

Well i mostly either use water or earth at the moment i usually check in a team generator what pet comboes best with what but i noticed some pets seem to be more usefull then others .

true i got rhino and he is now useless for me