Very odd! Because it clearly states in the event that you get Bellona + Battle Maiden skin. I'm wondering if she won't be gotten until the 3rd when the event officially starts? Meanwhile I'll see if I can find any information regarding this!
This rotation and gear is known throughout most of the crafting community. Mithrie isn't the only crafter out there and you'll find that the knowledge was circulated way before he created his videos. I am glad people know about Mithrie. His videos are really helpful.