This was posted in the 2+2 forums, and I thought it was interesting so I'll answer it here:
"XXX is the most loose-aggressive Omaha8 player on FTP, particularly in heads-up games. His BB vpip/pfr is 74/60 and his SB VPIP 98/97. He bets, raises, and reraises fearlessly. how do you counter him?"
The main strategies against players like this are:
1. Don't go on tilt. If you dont do this the rest won't matter.
2. Understand you will have high variance vs his style, and can swing up and down quickly
3. Realize that his range through the turn is extremely wide (assuming he continuation bets on virtually all flops, which these players tend to do), so you must be willing to call down much lighter on the turn/river than "feels" right
4. Trap more vs his style than others, as he will do the betting for you.