Dynasty Warriors 9 - Dong Bai - Level 1 to 100 - Ultimate Difficulty

Equipment
Godly Flail EX (ATK 408 / DEF 216)
Gems (Fire / Lightning / Poison)
- Toughness +16
- Musou +30
- Attack Speed +5
- Attack +42% with elemental
- Defense +29% with elemental
- Musou +7/sec. with elemental
- Attack Speed +14% with elemental
- Trigger Attack +81%
- Flow Attack +40%
- Special Attack Damage +18%
- Musou Attack Damage +70%
- Assault Damage +18%
- Counter Damage +20%
- Elemental Attack Damage +4 during a Counter

Accessories
- Heaven & Earth Gauntlets (w/ Allows you to jump at any time while attacking)
- Warrior's Plate (w/ Speed +13)
- Warrior's Plate (w/ Speed +19)
- Pike of Judgement (w/ Restores +2 Health every 1 sec)

The flail is a very well-rounded weapon, it's got attack speed, range, mobility and damage. Knock-Down is a very spammable attack, it happens fast, hits twice and it's easy to adjust your positioning while attacking at the same time with it. Her Special Attack is very good at crowd control, but only for what's in front of her, if using it while surrounded then try blocking after it is finished. Her ground Musou has a really long cinematic and good range, but it really doesn't deal too much damage. Her Air Musou deals more damage than the ground version and it has a much better hitbox for both the initial grab and final hit which is a huge ring of fire. The Air Musou is kinda magnetic, even if it may seem you're gonna totally miss, it will usually find a way to somehow land on somebody.

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I pick Gem elements based on the character's Musou and Special attacks.

Why not Musou difficulty? Because it's just a grind fest, not actually difficult. You also get the same experience rewards as Ultimate.