That happened to me too. The Legion models are not the right kind of plastic for cement. Super glue will work much better.

Try to clean off what you can first.

Yeah last night before going out I bought some gorilla glue and this morning cleaned up as much as I could with a nail file before gluing. So far so good.

I glue them to bases and assemble before priming. However. Figures with capes I don't glue fully together before priming. This usally mean assembling from the waist up, gluing the feet to the base, and dry fitting the body to the legs for priming. When that coat of primer dries I pop the legs off the body and lay the body down faecup and prime again to get all the spots in the legs and the inner cape. Then when that dries I glue them back together.