Okay so there are a lot of problems with the Monolith of Storms sets, it's definitely in the bottom third of the class sets.
ZOS has already identified two really good changes - allowing the set to crit and adding a self-bonus modifier. The set damage definitely needs to be addressed since it is right now far too low, but the set still has a major issue in the conflict between the class identity of high mobility and the class set of stationary monoliths that encourage you to fight in a single small area.
Currently, single monoliths give you nothing at all. Adding a self-bonus modifier might help with that, but there really needs to be some significant, tangible benefit to as a highly mobile Sorc confining yourself to one small area. I would suggest that the set grant you Major Protection while "nearby" the Monoliths. Major Protection wouldn't be too strong since it is already reasonably easily accessible though Flare, but is hard for Sorcs to squeeze in due to bar space limitations, and it would really help address the conflict between the class identity and the gameplay that the set enforces.