Ignoring the Impure World Reincarnation, it would probably look something like this.
The first ray of morning sunlight shone upon Madara Uchiha's face.
His two Rinnegan erupted with an incomparably sinister purple light.
The calm ground suddenly began to shake violently, as though some indescribable thing were about to tear the earth apart.
Affected by the disturbance, Tobirama Senju's eyes changed as well, blue Rinnegan appearing within them.
The yin energy continuously seeping up from underground appeared almost tangible to the Rinnegan.
"Rumble!"
Under everyone's shocked gazes, a monster dozens of meters tall burst out of the ground.
"What kind of monster is that?!"
"It's terrifying!"
"It's practically an evil ghost from hell!"
It was not as though they had never seen Tailed Beasts even larger than this monster, but the dense aura it radiated filled them with such revulsion that they wanted to stay far away. Standing near it felt as though they might die the next second.
A black crown was adorned with two slender white plumes, with the character for "King" engraved at its center. Its eyes held the exact same Rinnegan as Madara Uchiha's, and its massive body was draped in a white robe.
The summoned King of Hell opened its Rinnegan and, like a deity, lowered its head to inspect the ants beneath its feet.
Then it looked toward the caster who had summoned it into the mortal world.
"Do what you are supposed to do."
Madara Uchiha met the King of Hell's gaze and spoke indifferently.
The King of Hell froze for a moment, seemingly not expecting this human to be so bold. What did he take it for?
Still, the other party had summoned it at the cost of his life...
After searching through its body for the souls it required, even the