As for the reason why Astolfo was trending? Well.
(NSFW warning) A
cosplay of Astolfo in a skirt revealed a photo of his genitals. The photo also included a large Monster can as a clear frame of reference. The viral tweet inspired jokes and artwork (both safe and decidedly
not safe for work) revolving around Astolfo and the Monster energy drink.
In other words, you could say it was just an ordinary day on Twitter.
Faye Mata took the incident in stride, capping things off with a gif of the character and a thank you for a. memorable day.