-This gold hued dragon knight wreaks destruction, demolishing entire battlefields. At a stroke of its sword, enemies crumble, not leaving a bone behind. -Encyclopedia
Grendel Banjax is a stronger version of Grendel. Its golden armor provides excellent defense against physical attacks. The best way to knock him out of the sky is to hit his sword back at him when he throws it at you. When you do that he will be shortly grounded. Don't bother going to attack him when he is on the ground unless there is stars above his head. When you see the stars aim for his sword in order to break it as this is his only weak point once the sword is destroyed. Once you've accomplished that, go for his wings. That will make him unable to fly when both are destroyed and he doesn't restore them nor his blade when you destroy that. His sword is golden too, and it only takes one damage from every hit you do unless you use magic or break it. When he charges at you from the sky with his sword sideways dash at him and then quickly roll diagonally to the left or right while still going forward.
attacks: See grendel