A recurring villain?

Unlike Nichtmare Moon, Discord, Chrysalis, and Sombra, who were antagonists for a two-parter, I’m talking about a major villain that constantly antagonizes the mane 6 throughout the season.

The closest pony we ever had to one was Diamond Tiara, but she’s in the wrong age group.

As long as its the evil male Six I always wanted

I would love an anti-Six, as tired an idea it is. One that bands together to hate and mess with them but grows a bond as strong as theirs by the end of things.
 
Perhaps their greatest achievement would be to wield the elements themselves for one crisis and have the mane six owe them one.

I’d love a recurring villain, as long as he has an interesting personality. I don’t want some boring bully character like Diamond Tiara.

An antagonist earth pony would be sweet.