Bounen no Xamdou, A.I.C.O.: Incarnation Recommendations
-Both Original ONA's by BONES
-Both have the same series composer according to MAL
-Both have SCI-FI foreign matter or aliens that are connected to the main MC
-Both have a secondary MC more familiar with these matter or Aliens
Honestly they're almost the same show. However, I feel like Xam'd had a better cast of characters, better music (Although the OST for AICO is good), a more original looking Alien or matter, and in my opinion, a more pleasing aesthetic.