The Sea of Blood stage in Mortal Kombat 11 actually references Geras’ fate at the hands of Raiden.
Be warned, there are some big story spoilers here if you haven’t yet finished Mortal Kombat 11’s story mode.
Geras is a new character introduced in Mortal Kombat 11. On the side of Kronika, the big bad keeper of all things Time-related (and also the main boss of MK11’s story mode), Geras is a bit of a scholar. He’s studied history throughout the ages as Kronika’s first construct. A timeless creature, he reanimates after every death and is apparently on his “billionth” life cycle.
Judging by how violent the Mortal Kombat series can be, Geras probably needs to reanimate several times a day.
That Geras is immortal proves to be a very important plot point later on. During Raiden’s story, Geras shows up to defeat the God of Thunder as he leads the combined forces of Outworld, Earth Special Forces, and Shaolin Monks as they assault Kronika in her keep. Raiden being a god and Geras being a weird reanimating golem, Raiden defeats him handily only to have Geras comment that he is unbeatable due to his ability to regenerate.
So Raiden wraps him up in a chain and tosses him into the Sea of Blood, where he sinks forever. The Sea of Blood is apparently without bottom, and since Geras can’t drown, he’s neutralized in a very creative way.
Which is actually showcased in the Sea of Blood stage. Reddit user Gggg_high points out that in a post to the Mortal Kombat subreddit that one of Geras’ intro lines reveals what happens after being tossed into the ocean. Apparently, he became “food for a passing leviathan”, which you can see on the left side of the stage. On the right, you can see the iron anchor that Geras was wrapped in while sinking in the Sea of Blood and just before becoming giant fish food.
Evidently, Geras is eventually rescued by some passing blood fishermen. But it’s a neat little detail that reveals the added depth NetherRealm likes to add to each stage.