Lots and lots of Guass weapons. Load up on warriors, destroyers and Immortals. Remeber with Guass weapons, against troops a roll of a 6 to hit is an auto wound regardless of weapon str or target toughness. If you concentrate your firing from each of your units on specific units as they are approaching, and dont stop til they are eliminated or broken, you can prevent him from hitting your lines in mass. Also as he approaches, when he gets 18" away, move your warriors up 6" and rapid fire him before he gets the chance to charge. Even if he does charge, it will be with less men in the squad. When you set up your army, form a fire line around a Monolith keeping all your warriors within range of its teleport and Lord with Orb. Dont spread your army out accross the table, as this allows him to pick out specif targets. This way if he charges you, and all of your units are close together, you can support each unit. As a unit gets charged, port the survivors back out and shoot some more. Against Marines your best bet is to stay out of CC and have lots of shots going at him. Use the numbers game in your favor, and you should fare pretty well. Good Luck