i believe it was Kung Lao, although i'm not 100% sure.

For Deception it was Shujinko.

Deadly Alliance...I'd say either Kung Lao, Kitana, or maybe Raiden.

In MK:DA, it seems to be Kung Lao guided by Bo' Rai Cho.

As for MK:D - Shujinko, obviously.

According to her Konquest, Kitana was too....although Bo' Rai Cho's Konquest suggests she didn't finish her training. It's also implied she was the one who fought Quan Chi.

I guess you could say the hero was Kung Lao and the heroine was Kitana.

Deadly Alliance had more than one main charachter not just one.
I believe they were the group in the intro.

I suppose Kung comes to mind in the first place. He's the one who fought in the honour of the previous main character - Liu. It simply seems like he replaced him.
Moreover, his and Bo' Rai Cho's endings suggest Kung Lao's protagonism, while Kitana's is all about Goro And although the Konquest story is an interesting one, it's more like an addition to the main thread.
But looking at Deception's intro, I guess you could say that the Thunder God was the main hero back then, 'cause in the end only he stood between Earthrealm and total destruction.

Well in MK:DA Quan Chi and Shang Tsung have won so I dont think there's a main character at all

Kung Lao and Bo' Rai Cho I would say with the same reasons most of you posted.

Though In the End Raiden was the hero.

Well I guess id say for MKDA- Kung Lao and for MKD sadly it would be Shujinko.

I like making Shujinko kinda like a monk, though he is to much of a ass kisser...he suck up i dont like it