Well since Kunkka is an admiral, a sea voyager, and Morphling is the malevolent sea itself(or an alien made out of water, but as a basic idea, he is made out of water), they should have an special interaction when killing each other or when meeting up as allies:

Enemy:
I. Morphling : Kunkka, your navy is no match for the open sea!
: Kunkka, carrying your armada gave me a back-ache!

II. Kunkka : Morphling... not even the sea itself can stop me!
: A claddish soul is forever bonded to the sea!(refering to the Tidebringer)


Allied:
I.Morphling : Ah, Kunkka... set sail, the seas shall be calm for you.
: Maelrawn shall not bother you again.

II.Kunkka : Ah, Morphling, the sea itself is on our side.
: May we drown our enemies, Morphling.


Please tell me what you think about it( they might not be the best quotes, so I'd also like your suggestions too).