COR is special like DNC and SCH because it is ACTIVE and caluclating, not mnk (attack, ws). I would like something more active with XI rolls.
Not to be too complex, but I think it would be interesting to give COR a JA that is similar to DNC's Flourish. Everytime a COR hits an XI, it earns a point for that JA (like steps do). You can then use the JA to use those points like:
1 point = add a 2 automatically as your next Double Up (like Snake Eye does 1). This gives more flexability because COR can then add a 1 (if did that merit), a 2 (this new JA), or a 3 (using Snake Eye and then the JA)
2 points = extends last roll by 50% (have to be in Double Up status). A 5 minute roll would then be 7.5 minute (and more if the COR merited Winning Streak)
3 points = Adds an additional 15% to last roll (in Double Up status). For example, a 25% DRK roll would turn into a 45% DRK roll, a 12% WAR roll would turn into a 27% roll, etc.
You can store a max of 3 points, so a COR can't use 3 points to add 15% potency and then turn around and add 50% duration too. And it's not overpowered considering would take awhile to get three XI's (I imagine more people would spam the 1 point version to keep getting XI's).
Also, you would have to lose the "saved points" on a Level Sync. When SE implimented the "double duration", COR would just lvl sync, unsync and keep retrying for XI's every 30s.
--Edited to remove lvl suggestion on the JA. who subs cor lulz ---