Zip Slasher

The Zip Slasher (ロールスラッシャー) is an Emblem Heartless that is found in Kingdom Hearts 358/2 Days.

Kingdom Hearts 358/2 Days
This sword-wielding Heartless's skillful defense makes it tough to finish off. ''Its spinning slash has the added effect of damage-draining HP from victims. Watch for it, then evade or deflect it with a block.''

Strategy
The Zip Slasher is indeed powerful, as it has great amounts of HP and high damaging potential. It immune to all forms of magic, so physical attacks with your weapon are your only way to damage the Zip Slasher. Also only use limit breaks when it is low on HP or on it's last HP bar, as it can still attack with its deadly combo. You can sometimes freeze it with upgraded blizzard spells but it doesn't stay frozen for long so be prepared. It does not hesitate to attack, immediately lunging at Roxas. This tactic is easily predicted, as the Heartless's blades glow green, and can be avoided with careful timing of the Guard or Dodge Roll abilities. The Zip Slasher's technique is to do a powerful spinning attack, then lunge toward Roxas with its powerful sword-like arms. It should also be noted that the best time to attack this Heartless is when it pauses after each attack, which is about enough time for two combos. Despite its great amounts of health (a grand total of 11 HP Bars), the Zip Slasher can be defeated easily when the player revisits the mission. Also, the Zip Slasher will heal whenever it lands its powerful combo, which can make this a tiresome battle. A well timed blizzard spell has the potential to freeze him, leaving a few seconds to deal huge damage. You can usually eliminate 2 or 3 bars if you have a decent weapon equipped. The best time to blizzard him is right before the second part of his attack, where he lunges both blades at you.