Flame Core

The Flame Core is a Pureblood Heartless that appears in Kingdom Hearts 0.2 Birth by Sleep -A fragmentary passage- and Kingdom Hearts III.

Kingdom Hearts III

 * Fire Blow (ファイアブロー)
 * Fire Throw (ファイアスロー)
 * Rush (突進)
 * Meteor Attack (メテオ攻撃)

Kingdom Hearts 0.2 Birth by Sleep -A fragmentary passage
Attacking it with melee attacks works to wear down its HP, but at that point it lights itself completely ablaze and charges around, damaging Aqua. Three shots of Blizzaga can slay a Fire Core without much trouble.