I believe that the units in such a castle could be:
1.Frog-Toad(jumps high and can jump over an enemy stack)
2.Salamander...(can be resurrected once per battle).
3.Turtle-Sea Turtle(moves slowly, but has a high degree of defense and low susceptibility to magic)
4. Mermaid-Siren(possesses a deadly gaze)
5.Crocodile...(Always deals maximum damage)
6.Octopus-Cuttlefish(attacks everyone around, can disappear from the battlefield for one or two turns (by choice) once per battle).
7.Vodyanoy....
Don't judge too harshly. I'm writing down what I'm thinking at the moment. I hope you will help me.
I really want this castle (if it exists) to be located underwater!

