I need to find how to mix these two dragons so I can finish this battle.

I’m doing everything I can please someone help ?

Go to the dragon book, click on the filter for dragons you own, then click on the elements and select war/sea. Next find the dragon you want to use, if you have some but they are not the right level, level up the one that has the highest rarity as it might prove to be useful later on.

They are opposing elements, so you can't breed the two single element dragons to each other to get a hybrid. You will need to chose something that has two (or more) elements - one of which is sea, and another dragon with two (or more) elements - one of which is war, and put them together and hope. It may take many tries. Try to use dragons with the undesired element that will give you short breeding and hatching times so you're not wasting too much time.

You might have already had success getting a dragon from an event that has war and sea in it. That will save you the most time, especially if it it one of the high rarities or has additional elements that could come in useful in future quest requirements.