At 75 Cap the SC system ending with Light and Darkness made since. But, since we've proceeded well past that point and considering some of the things introduced thus far I didnt think adding another teir to the system to be out of the question and possibly motivate players to use SC's more often. The SC system so far has kept light and dark elements seperated, for Teir IV i'm proposing mixing them and having added effects to make them unique as well as their respective elements being the MBs. Being late added SC's limiting creation of the SC to ws from Relic/Mythic/Empyrean/290Skill seems practical. The added effect should probably last roughly 20 seconds so its not overpowering.
Fire + Earth > Magma with added effect Curse.
Thunder + Water > Electrocution with added effect Terror.
Dark + Wind > Pestilence with added effect Plague.
Ice + Light > Prism with added effect Amnesia.