To beat Gregar, stay on your toes and use the Slashman link navi with Megaman, because it does 80-100 damage and if you move quickly should beat him fairly easily. Remember to save before the battle because it might take 2-3 tries before you can get the hang of it, but when you do, it'll be easy to win. If you don't have Slashman link go to Green Town and help the lady giving cooking lessons. Once you beat the challenges you'll get to use Slashman as a link navi.
Submitted by BobbyBouche
Mega Man Battle Network 6: Cybeast Gregar Unlockables
GamesRadar+ is the premiere source for everything that matters in the world of video games, TV, films and more. Casual or hardcore, big screen or small, console or handheld, blockbuster or cult classic - whatever you're into or whatever genres you love, GamesRadar+ is there to filter out what's really worth your time. We deliver breaking news, the best advice, the most in-depth features, expert reviews, and essential guides for all the entertainment you love.