[Homura7]

I have a guess...

Spoiler for spoiler:

Let's take a closer look at how Saten's abilities are named:

Fourth Wave: Consist of absorbing termal energy and releasing it in the form of a powerful attack. Absorbing the heat has the aditional ability of freezing.

Fifth Wave: Unleashed with no need of termal energy. Saten unleashes this powerful ability with no need of any external factor. As a result and since he used his left arm, the bandage shattered revealing the tatoo.

Yes, Saten's left bandage shattered not because the tattoo, but because he used his left arm to unleash the Fifth Wave. Had used his right, the result would have been same.

So I'm asking, Saten's abilities are named in numbers. What if his fragment is not absorbing kinetic energy but something bigger? Like having the control over many external factors such as the heat, the water, etc.

Also, where're the First, Second and Third?

Spoiler for spoiler:

Also, how many manga out there have an old man in a business suit fighting a cute lil schoolgirl? Was not really expecting that .

Not many indeed.