If you want this fight over quickly you use Ikky(1,1,1). Last time I tried this the fight felt like it took FOREVER. I should probably add I use a pocket cannon(1,2,1) and a Dream Whelp(1,2,2) for dealing with the backline. Pocket cannon can demolish beast and flying as well as it has a lot of health.
This worked with a Tiny Green Carp! My ikky was dead, my Syd underleveled, but with Water Jet/ Healing Stream /Whirlpool and two crabs with arcane moves in the back in case of backline fliers the fish was able to solo the encounter! I know it's a rare pet, but confirming it's viability!
Healing Stream only works on aquatic pets, so they will be healed and not die to Dreadful Breath from the boss. Any other pet classes would either die or be very low.
But that is kinda irrelevant as i've never had Syd the Squid die in this fight, also Syd uses Tidal Wave and that kills both deviate flappers, or at the very least get them so low they only require 1 hit to die.
I think you must have made a mistake somewhere, since Syd has soloed the fight for me 100% of at least 20 tries.
This strat worked great for me even with low hp aquatics, but I can see how putting two high HP turtles in the backup slots can be helpful (they're only there to soak aoe dmg since Syd can solo it all, so their abilities don't matter).
Love this strat, btw! Thank you!