Name the Anime!

[ChaosArchon]

So I know I've asked this forum occasionally to help me find out the name of something cool I remember from when I was younger and this is no different although I'd have to say this is stretching the skills of even the most avid anime fan.

Ok so I remember there was this castle under siege by the sea and it had metal hexagons acting as a shield for it on the cliff side... and that's it, that's all I remember although I know magic was involved and the main character was bound to some mystical being but that's about it.

[Mx.Silver]

You want to give any indication of how much younger you might have been?

[ChaosArchon]

It would have been at most 8 years ago... I feel like Blue might have been part of the name

[Hopeless]

My first reaction was King Arthur and the Knights of Justice or that cartoon involving a group of time travelling American College Football players being summoned by Merlin after King Arthur and his knights were turned to stone and Camelot beseiged... yes well not anime but as I said my first thought.

Nadia and the Secret of Blue Water?

Not a series I've actually watched but I've heard about...

[ChaosArchon]

I feel like the name might have been Blue Dragon or something but that's a video game not an anime

[Zaydos]

There was a Blue Dragon anime in 2007-2008 or 2009 (I'm half asleep and wiki is confusing me at the moment).

[ChaosArchon]

Maybe that was it then, I just googled it but it won't show me any images of the castle so I have no way of being sure.