Board Thread:Questions and Answers/@comment-24975288-20140815124236/@comment-5150583-20140815131917

Normally I believe Osmosians can only gain a fraction of the species power and comes with their weaknesses too. Aggregor was able to build a machine to get around the "only gain a fraction" part, but he still needed a certain kind of  Celestialsapian for his plan to work

Also since their powers can be absorbed that implies a weakness which OPs don't have.