What is the fastest way to reach 50 on dynasty warriors 6?

He Fei Castle on Wei's side.

Just rush it and go straight for Sun Quan.

If you kill him fast enough, you get a great time bonus and complete all three targets for more XP.

Use a second control to gain more XP on another character, If you have a second person, just make them run to the water in the middle, they can't get hurt that way.

If you're feeling confident, you can play on Master difficulty, It gains more time XP and can also gain 50% more XP when you get XP pouches.

I have a horse that has ability "Steal Hoof", meaning it can run over and enemy including officers, So I just run down there and deal great damage to Sun Quan on Master difficulty just by running him over.

Also, The reason I said Master instead of Chaos is because Master gains you the exact amount of XP as Chaos.