Multifarious is when there are different matters brought into a case that are not related to each other other or to the basis of the case. This is also commonly referred to as a misjoinder. It weakens any case and the judge will act to sort through multifarious streams and remove them from the case.
Civil suits that have multifarious streams of claims in them will be more expensive and take more of the court's time. So the judge acts to determine when these streams happen and to stop them from proceeding or being included in the claim.