Assailant
The SHSL Shadow Alchemy Stand Using Lab Member
Also, I was thinking. You'll see in my timeline coming out soon that the war was pretty soon after Discord (Like, twenty or thirty years after.) So isn't it possible that Silver and Arc would know of the legend of Eclipse? It was pretty soon, and many of the living ponies would have been alive when he was ruling (I dunno how long Discord's reign lasted, so maybe not?) But word of mouth would probably still be alive.