Ok so imagine the Avengers(Thor, Iron Man, Black Widow, Hawkeye, Captain America and Hulk) are a part of the Half Life universe. The Combine have just opened their invasion and the Avengers arrive on the scene of the largest concentration of the Combine's forces to try and halt the invasion. We know that even though the Avengers, despite their power, wouldn't be able to hold out forever. How long would the Avengers survive against the Combine forces?