Yeah there's limitations. If a person is too powerful I can't hold them in the sphere. It causes them damage but I can't totally phaselock them. It does work on animals but the same way with humans. Too powerful and they get damaged not locked. Machines....I think it depends on size, maybe? I can phaselock robots but not vehicles or ...giant robots or aircraft. They still take a lot of damage though.

Also I can only use my power so many times in a row before I have to like rest that part of my brain for a minute or so. The stronger I am the more I can use it.

Also if Lilith's powers are anything to go by. The more I'm able to advance my powers, the more I'd probably be able to phaselock bigger and more powerful things. But since I can't use Eridium that will probably take years more practise and training.

[One of many reasons why she would like this place more if she had them. It's not even using them against people or things here. She just wants to continue training.]