Board Thread:Improvements and Issues/@comment-3095304-20130316210449/@comment-1776824-20130316211835

Well, as far as we know, a Dragon can only control one element. As for the Lacrima, the only known people who have a Dragon Lacrima implanted either have just the Dragon Lacrima, or have the corresponding Dragon Lacrima. No one has had a different, or a second, Dragon Lacrima implanted into their body. Meaning, in the end, I can't answer your question, solely because none of this has ever been touched upon in the manga.