In Sonic Forces, about a month after Infinite's last meeting with Shadow, Eggman launched an attack on the City. When Sonic showed up to stop it, Infinite appeared to fight him, alongside Phantom Copies of Shadow, Zavok, Metal Sonic, and Chaos that he had created. Overwhelming Sonic with his power and Phantom Copies, Infinite defeated and captured Sonic.

After imprisoning Sonic onboard the Death Egg, Infinite and Eggman went on with their conquest unrivaled. With Infinite's power and his Phantom Copies, the doctor was able to conquer over 99% of the planet, resulting in the Eggman Army controlling that much of the world. In the meantime, Infinite worked alongside his Phantom Copies to instill fear into the subjugated population. However, a rag-tag Resistance founded by Sonic's friends was soon formed to continue the fight for freedom, though they proved to be of little threat to Infinite.

In those six months Infinite had frequent meetings with the hedgehog for a number of reasons
this was one of those meetings

Somewhere deep within the death egg we see sonic the hedgehog chained up still struggling to get out of his grasp and be the hero he always is, he was always strong like that. But to end these far-to-long moments of silence was the familiar stomping against the cold tile floor leading to the appearance of the master of illusions himself, infinite

Infinite:
Aww, look at you, the "little blue savior". All alone, With no friends! ahahah And no way out.

Sonic:
Why are you doing this? You're a mobian! Just like me. It's only a matter of time before Eggman gets rid of you like he plans to do with everyone else!

At that infinite charges towards the hedgehog only to abruptly stop inches away from his face

Infinite:
I'm nothing like you! I'm more than you'll ever be!

[INFINITE]
It's time you learned a lesson,
It's time that you understand
Don't ever count on anybody else
in this or any other land
I once hoped for friendship
to find a place among my kind
But those were the childish wishes
of someone who was blind

Open up your eyes,
see the world from where I stand
Me among the mighty,
you caged at my command
Open up your eyes,
give up your sweet fantasyland
It's time to grow up and get wise,
come now little one
Open up your eyes

We all start out the same
with simple naive trust
Shielded from the many ways
that life's not fair or just
But then there comes a moment,
a simple truth that you must face
If you depend on others,
you'll never find your place…

...

And as you take that first step
upon a path that's all your own
You see it all so clearly,
the best way to survive is all alone

Open up your eyes,
see the world from where I stand
Me among the mighty,
you caged at my command
Open up your eyes
and behold the fading light
It's time to grow up and get wise,
come now, little one
Open up your eyes
Open up your eyes!