He's a strong Legendary character. He excels in TW where his Omicrons are.
Personally, I've never lost a GAC battle with him. He has strong damage and with Temple Guards Omi, you can guarantee full banners against any team without a dispel.
The individual character is mid tier, but the diversity provided by his teammates makes him a GAC and TW powerhouse. I have also had great success in Conquest with them. I also run every GC with them to help get data on matchups for future PvP use.
Is he CLS or JKR, no.
Is he Grand Inquisitor, also no.