Khilafat can only be divinely guided. It is only established with the will of Allah so simple answer to your question is Spiritual Leader.
so a khalifa gets some kind of divine guidance.. like ilham rite... actually i remember watching your channel in chitral a few yrs ago.... chitral is in northern pakistan... very remote ( i m impressed how it broadcats everywhere).. but while watchin the chaneel, i felt it, n honestly, dont u think your present khalifa is a bit rude.... absolutely no offenece intended brother... so i was thinkin may be he was some kind of worldly leader or somethin... and one important question... who has the absolute right in your jamaat to interpret the holy quran?? sorry but i was curious to ask these questions.... :)