Deadlock i noticed something with pets, it was pretty cool too, but im not sure if i wanna go further researching, so if u have pets with the same skill usually it can require a different pet, for example
The Dark bat with the merman
-Both of them are lvl 60
-One requires machinery 30+ for resonance (Merman) and one requires a +10 undead (dark bat)
-When i have a lvl 20 Zombie, and Darkbat I have a lvl 1 renosance
-Darkbat is still my main pet in the middle
-When u add a merman lvl 60 and machinery 30, (merman doesnt have to be 60)
it adds another level to resonance
-This concludes that other pets in the formation also have their soul skills activated by reacting with other pets
When u said certain formations, i think u only meant the 4 skills u can get from each, but i dont think u implied the reaction of two sub pets