#4. The Fiend was able to take over the mind of "The Messiah" Seth Rollins
The Fiend defeated Seth Rollins at Super ShowDown in 2019 to become Universal Champion. The defeat changed Seth Rollins and set him on a path to become the "Monday Night Messiah", or just "The Messiah" as he's now known.
Rollins went on paternity leave from WWE back in November. It's entirely feasible that The Fiend continued what he started with Rollins earlier in the year and pushed his new "vision" character.
This could explain why Alexa Bliss was eliminated so quickly from the Women's Royal Rumble match because The Fiend was focused on Seth Rollins making his return later that night.
Rollins' character has been much more intense since he returned to WWE last month and could be referring to The Fiend when he talks about "The Greater Good" and "Embracing The Vision". After all, Rollins has already been defeated by The Fiend and knows what awaits on the other side.