O.N.I.C Share definition Flag Only nigga in charge. Typically refers to a person several steps above an alpha and even higher than a H.N.I.C (Head Nigga In Charge). Gurren is the O.N.I.C in Seraph of the end. O.N.I.C by Booligan123 November 4, 2018 0 0 Get merch Get the O.N.I.C mug. Buy Now — $32.95 See more merch