Berserker

The Berserker is a high-ranking Nobody controlled by Saïx that is found in Kingdom Hearts II.

Locations

 * Twilight Town
 * The World That Never Was

Kingdom Hearts II
''A berserker. A high-ranking Nobody. Its attacks are hard to read as it is dragged around by a cursed hammer.''

''Attacks from the front will only be parried by its hammer. Knock it down to make it let go of the hammer. Then pick up the hammer to unleash a flurry of attacks with Berserk.''

Strategy
The Berserker has very strong attacks and has an equally strong defense. Moving in for a head-on attack can be risky although the proper strategy is needed. First you attack with a combo. Then grab the Claymore and combo. Continue this until dead. If in The World That Never Was, use Riku's Limit to finish the job. Another good way to deal with them is to come in close, reflect its attacks, and wait for the reaction command to show up. Using it will greatly diminish the Berserker's health as well as any other enemies that you capture with it.

The Beserker will often transform itself into a hammer-like object before crashing down multiple times. This can be almost impossible to avoid, although using "Quick Dash" is your best bet.

When Berserkers appear some of them might appear without their Claymore. The Claymore would materialize right in front of them, and if any character is between the Claymore and the Berserker, damage would be dealt. When the Berserker holds its hand out the Claymore will rush to it and damage anything in its way.

A good alternative is using Thunder or Blizzard at a distance to help preserve HP or using Magnet followed by a limit or Thunder to finish the job.

Another strategy would be to use Wisdom Form, for its MP-free long range attacks and accuracy. Its attacks can hit a shrunken Berserker from far away, which takes away the risk of being parried and countered. When it gets small limits like the solo Trinity Limit can still attack it and possibly kill it.

When using a special attack (which is like the "Berserk" reaction command), it becomes small in size, hanging from its claymore-like weapons with its small hands.

Etymology
The word Berserker also comes from the viking warriors called "berserkers" (shortening of 'bear serk', the name of the clothing they wore) who were infamous for fighting in a violent rage, recklessly charging at their enemies without armor or any other protection, and seemingly without concern for their own health.
 * The Berserker is based on the Final Fantasy job class of the same name.