While it is a good thing to wikify (add links) link you did here, there are a few things to remember:
Try not to link to disambiguation pages. If you are working on a specific version of a character - the DCAU version of Brainiac in this case - the links should point to other DCAU pages.
Do not over link. Linking to both Kal-El and Superman in the History is redundant. Pick only one. Generally we use the first occurrence of the character.
Do not wikify common terms such as "drone". Most times we will not have, and never will have, a page that provides an definition of that type of term. "Drone" is a case where we do have a valid link, but it redirects to a character that is totally unrelated to the DCAU.
Sorry, but I didn't think it would be that big a deal, since on the Etrigan page, there's a link to Etrigan, like it goes in a circle. On the Quotes page, there's numerous links back to him. Is there a difference that I can't see?