Rubeus was downright evil and manipulative. He sent the four sisters to do the work but planned on getting all the credit for himself if they were successful. He deployed them to potentially dangerous situations with the thought that they were expendable. Rubeus would then claim the fruits of their labor if they died.

Rubeus knew that Cooan was in love him. He used Cooan's feelings for him to control her, but he broke her heart in the end by telling her he did not do "stupid things like loving somebody...".

Rubeus was able to capture the sailor soldiers and use them as bait for Sailor Moon. Sailor Moon and her group managed to escape Rubeus' exploding UFO, but Rubeus was left there by Esmeraude to die because of his failure.