I really, really wish the folks at Midway would have the Lung Hai sea beast in MKD! It had such great potential! Here are a few ideas how they could bring it back:

1. Non interactive (MKDA-like) environment

They could just bring back the Lung Hai temple in MKDA, touch it up a little, maybe change the weather a little, and everyone will be happy! We get to finally see a sea serpent fatality in it's glory! Wooo!!!

2. Interactive environment #1

The battle arena would be on a large platform or ship, at sea. The Sea beast is already interactive. As you fight, the (large) creature randomly rams the platform /ship, chipping off pieces as it goes. This means that the fighting arena gets smaller, and smaller, and smaller, meaning that the deathtrap area gets larger and larger!
If you're unlucky, your fighter could get caught in one of the sea beast's ramming ordeals, and get killed instantly. Alternatively, the match could continue, until one of the fighters gets kicked into the water! Well, you know what happens next.........

3. Interactive environment #2

The battleground could be on a multitiered cliff by the edge of the ocean. As you fight, you fall to a lower (and lower) ledge. The lowest point is of course the water down below. Once a fighter hits the water, our sea-serpent performs a kick-@#$ stage fatality!

Oh! Please have it in MKD! It was such a waste not to have it in MKDA! Pretty pleaseeeeeeee?