This would be a fight to the death for Lui Kang. Dark Seid is considered one of the bosses on the upcoming MK game, Mortal Kombat vs. DC Universe. But I think Lui Kang could take him. Lui Kang compared to Dark Seid, is the strongest human alive or dead. But, in death, Lui Kang is as strong as a god. He is quicker and stronger than anyone. But he was taught all of his skills from no other than Kung Lao. Raiden also taught him how to release his true power. But Nightwolf taught him how to channel his animality. (Dragon) We can say that he was taught well alive or dead. Dark Seid would be a challenge though because he is kind of stronger than Lui Kang. But Lui has the power, strength, and courage to go up against someone who would give him the challenge he is looking for.