Osiris overreacts to Clovis’s taunts precisely because they confirm what he sees when he looks in the mirror. He used to be one of the two strongest Warlocks to ever exist which undoubtedly played into the arrogance and obstinance he exhibited before losing the Light and being hijacked by Savathun. Now all he brings to the table is his intellect which doesn’t impress Clovis much. It’s like a D-list celebrity yelling at a barista for not showing the proper deference, “Do you have any idea who I used to be in the nineties!?!” Perhaps the most famous Warlock for hundreds of years, he spent one year with a Hive God inside him, another year in a coma and has now had all of one week to get used to being awake, in control of his body and Lightless. May take him a bit more time to drop his inherent arrogance. (΄◉◞౪◟◉｀)