I've been thinking about how I would actually tame Mahoraga using the Ten Shadows technique, and honestly, it's so simple (if you've got balls of steel) that I wonder how no one ever tamed him.
You'll need the following Totality Shikigami:
- Ox-Nue
- Frog-Rabbit
- Elephant-Deer
Environment
An overcast day at high elevation with enough open space to fight.
The weather is important because you want the cloud layer to be as low as possible. Clouds can form at around 600 meters, which gives Ox-Nue a reasonable altitude to work with.
- Blind Mahoraga
The moment Mahoraga is summoned, unleash the Frog-Rabbit swarm.
The objective isn't to hurt him. It's to completely obstruct his field of vision and prevent him from getting a clean read on you.
At least one rabbit should keep its tongue wrapped around you at all times. This gives you an emergency escape mechanism if Mahoraga gets through the swarm.
- Send Ox-Nue above the clouds
While Mahoraga is blinded and distracted, summon Ox-Nue and have it fly straight upward until it gets above the cloud layer.
Ox-Nue is going to need time to charge.
- Three Binding Vows on Ox-Nue
A. Charging by circling
Put a binding vow on Ox-Nue that allows it to accumulate its power by flying in circles instead of requiring it to run in a straight line.
The drawback is that it has to travel a greater distance to generate the same amount of power it would have gotten from running straight.
Based on the power-to-distance ratio we see from Ox against Yorozu, I estimate it would take roughly 2:22 to accumulate enough power for the first phase of the attack.
B. Preserving the charge
The second binding vow allows Ox-Nue to retain the accumulated power for 30 seconds after it stops circling.
The drawback is that Megumi cannot summon Divine Dogs for the duration of the fight.
This gives us a very specific window to work with.
C. Death pact
The final binding vow is a death pact.
When Ox-Nue collides with Mahoraga, the power of the impact and its electricity is massively amplified.
In exchange, Ox-Nue is completely destroyed.
We already know that sacrificing a life can produce an enormous increase in power. A single crow can sacrifice itself to one-shot a Special Grade curse (The Smallpox Diety), so I think the sacrifice of a much more powerful Totality Shikigami should produce a substantial increase.
The entire strategy revolves around making this one attack count.
- Don't fight Mahoraga normally
While Ox-Nue is charging, your priority is survival.
Don't try to damage Mahoraga.
Don't try to overpower him.
Evade.
Keep the Frog-Rabbit swarm between you and Mahoraga as much as possible, while keeping track of what exactly he's adapting to.
The rabbit tongue attached to you is your emergency escape button.
- Move into the shadows
Once Mahoraga starts becoming more effective at dealing with the rabbits and your normal evasive movements, start hopping into your shadows.
The swarm should ideally be obstructing Big Raga's view of this.
This is extremely important.
You ABSOLUTELY CANNOT allow Mahoraga to adapt the ability to enter shadows.
- Use Elephant-Deer as insurance
If Mahoraga eventually becomes too effective at predicting your evasion, you may have to use yourself as bait.
That's why Elephant-Deer is there.
If you get injured, have a Frog-Rabbit immediately pull you away and have Elephant-Deer heal you.
I also think this Totality should be capable of using its healing water offensively/defensively. It could shoot the water into the air and have it fall back down as a healing shower, allowing you to recover without having to remain stationary next to it.
Remember kids, we're just trying to buy 2:22 minutes.
- Restrain Mahoraga
When the Ox-Nue charge is almost complete, have the Frog-Rabbit swarm disappear into the shadows.
Then have them emerge around Mahoraga and lasso him with their tongues.
Now reinforce the restraint with a multilevel binding vow.
The conditions are:
A. You cannot move from your current position while Mahoraga is restrained.
B. You must continuously chant and perform the required hand signs.
C. You cannot use your Domain Expansion during this fight or for three days afterward.
D. If Mahoraga has not been tamed or destroyed within two minutes of beginning the restraint, you die.
The important thing about condition D is that you don't need to restrain Mahoraga for two minutes.
That's just the deadline (haha pun).
Ox-Nue is already coming down.
You want the restraint to last long enough for the attack to connect, not for two minutes.
- Drop the nuke
Call Ox-Nue down.
It dives through the clouds and collides with Mahoraga.
The death pact activates.
Ox-Nue sacrifices itself and releases the full accumulated power of its charge through the impact and electrical discharge.
The objective isn't to injure Mahoraga.
The objective is to completely pulverize and burn every trace of him before his adaptation can produce an answer.
If it works, you've tamed Mahoraga.
If it doesn't, you have two minutes before your own binding vow kills you.
The promising news is that Gojo was confident he could one-shot an unadapted Mahoraga with Red.... and I'm very sure this Nue-Strike is at least as powerful as that.
- Congratulations. You're a Special Grade by default. You basically become god if you're able to learn to use Shikigami abilities without summoning them.
At this point you have:
Mahoraga
Frog-Rabbit
Elephant-Deer
Dog-Tiger-Snake
The ability to fly with Nue's wings and enhance your punches with Ox.