You don't know Metal Gear Solid 4

Eva… is "Big Mama"
MGS3's saucy double-agent is back, 50 years on, as "Big Mama." Guess? Her humpin' session with Big Boss in MGS3 was significant.

Raiden… has white "blood"
Raiden/Ninja coughs up white "blood," presumably after the Vamp scrap. Theory? He's not human, but a cyborg.