Megumi's "INCOMPLETE" Ten Shadows Technique

As we know of Chapter 212, When Sukuna finally switched to Megumi fushiguro making him his new vessel, we see Megumi reach the near peak of Ten Shadows. 

Even though he summoned Mahoraga as early as chapter 117, he still hadn't unlocked the true potential of Ten Shadows. The Shikigami he summones TILL NOW are:

1.Divine Dogs (玉ぎょく犬けん Gyokuken^?): Twin canine shikigami with powerful noses for tracking and lethal fangs and claws for devouring curses.^[130] The white dog was destroyed by a Finger Bearer but its abilities were inherited by its black twin.

2.Piercing Ox (貫かん牛ぎゅう Kangyū^?) is an ox shikigami that can charge with immense strength. It can only move in a straight line, but the longer its charge, the more powerful it is.^[58] Its physical strength is robust enough to match up against a reincarnated sorcerer from the Heian period.^[59]

3.Nue (鵺ぬえ Nue^?)^[131]: A winged shikigami armed with electro-shock wings that can carry people short distances. Megumi mainly uses Nue for scouting or to support another shikigami using its mobility.

4.Great Serpent (大蛇オロチ Orochi^?)^[132]: A gigantic snake shikigami that was used to ensnare Megumi's targets. It was capable of destroying low-level curses but only bound Sukuna momentarily before being destroyed. It is currently unknown which other shikigami inherited its power.

5.Toad (蝦が蟇ま Gama^?): A large toad shikigami with a long and powerful tongue that can grab people and pull them through the air. Toad's tongue can be used to pull Megumi or his allies to safety and then carry an entire person in its mouth if need be.

6.Round Deer (円まど鹿か Madoka^?) is a towering deer shikigami that can heal through reverse cursed technique. Its positive energy is powerful enough to cause another sorcerer to lose control of physical objects strengthened by cursed energy.^[57]

7.Max Elephant (満ばん象しょう Banshō^?): An elephant shikigami that Megumi dominated just before the Goodwill Event. Max Elephant has the ability to produce a massive volume of water from its trunk and its weight can be used offensively as well.

8.Rabbit Escape (脱だっ兎と Datto^?): A swarm of rabbit shikigami that Megumi uses as a distraction or to help him figure out his enemies abilities. Like the Well's Unknown Abyss, rabbits can be destroyed without any repercussions, allowing Megumi to spawn as many as he needs.

9.Eight-Handled Sword Divergent Sila Divine General Mahoraga (八やつ握かの剣つるぎ異い戒かい神しん将しょう魔ま虚こ羅ら Yatsuka-no-Tsurugi Ikaishinshō Makora^?): The most powerful uncontrollable shikigami that the Ten Shadows Technique can produce. Not a single user of the technique has ever been able to tame Mahoraga, including Megumi. He only threatens to summon it as a trump card if he feels he's going to lose a battle anyway, releasing it to attack both him and his opponent.

But this tells us that only 9 shikigami have still been summoned. This leaves us with ONE unknown shikigami that might be way stronger than Mahoraga. This tells us that Megumi's technique is still incomplete.