The Seven Glorious Infernos was the essence of the lifetime martial arts teachings of the Inferno Star Lord. It would be impossible for Mo Wen to learn it all in a short amount of time. In fact, he would be unable to master even one quickly. After all, it was a rite of passage martial arts. Only ancient martial art practitioners that had become immortal could practice it. Right now, he was far from qualified.
If he still insisted that he could practice it, he would most probably only be able to just about practice the basic chapters of Glory of Thunder, Glory of Wind and Glory of Cloud. He would only be able to practice the other four Glories by becoming an immortal cultivator and mastering the powers of heaven and earth.
The three tail feathers seemed to "understand" him very well, teaching him precisely the Glory of Thunder, Glory of Wind and Glory of Cloud.