I was going to mention it myself. The series is, in many ways, very much an Eyrie work--not just in themes and tropes, but certainly in the winking nods to other anime and sources--this is somewhat less obvious in the first series, which is more about taking the 'magical girl' formula and turning it about 75 degrees clockwise, but becomes far more evident in A's and StrikerS:

Signum is voiced by Kaori Shimizu, who also voices Lamia in Super Robot Taisen, and the two characters are very similar in many ways (And SRT series is also quite Eyrie-like).

Subaru is a nod to GaoGaiGar...

There's a ton of others but I can't remember them all.

Besides, you gotta respect a series that opens its second season with the main character practicing mental control over her magic blast and air-juggling a can 99 times, only to consider herself 'failed' when she misses the trash can. That's some serious stuff right there, especially when you consider she's basically 9 years old.

Going back to the older school--more obscure things like Yuugen Kaisha and Devil Hunter Yohko would make a fit now (less so in the original UF core days, but the series branched out from mecha-space action with a touch of mysticism quite some time ago, ne?)

I don't explicitly recall seeing any mention of Lost Universe outside of Truss getting the Swordbreaker and Canal, and certainly Dark Star would fit in somewhere as a Big Bad.

Metal Fighter Miku -- girls pro-wrestling in power armor? I'd be terribly surprised if -that- wasn't a big-ticket sport -somewhere- in the Eyrieverse.