They were not sent here, just like all divine entities like we humans, they descended from the top of the pyramid of energy, to the bottom of it, subconsciously, which are emotions like greed, jealousy, hate, pride, anger, fear and guilt. These emotions pulls you down from the cosmic dance of light to experience life as a mortal in a material body, but unlike them, we came here willingly and under God's mandate. They came here forcibly and cause of that, the form they took is too strange and otherworldly for us to accept or coexist with, that made us fight them and made them hate us the more, that we had to harness powers, knowledge and runes to exile them into alternate realities where they'll never have a direct contact with human beings ever again. This worked a bit but evidently not entirely, cause they have thrice the knowledge we have due to unlimited time and access to knowledge we haven't touched yet
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