Defeat Mistman V3 with S busting level.
First make sure you have an Elec style equipped. Then go into battle with a good snake folder (4 snakes;same code, 4 wood+30, geddon 2's, and a lot of area stealing chips). Keep adding stuff and stealing panels while you hunt for the good chips.
Use FstGauge in the Navi Custimizer. While in battle charge your charged attack. After Mistman uses or starts to use his tackle 6 times stun him quickly with your charged attack to avoid being hit by poison mist.
Repeat until your ready. Crack the panels with geddon 2 when your ready (its best to do this when your on the far right row to maximize the amount of places for snake to come out).
Use as many snake as you can to finish him off. I have gotten an S rating 4 times in about 10 battles using this stratagy and the others were all about 9.
Use ElecTeam style to get the V4 chip.
We have more cheats and tips for this game here, Mega Man Battle Network 3 White cheats
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