He refuses to take it off, and besides, if he did, it would start releasing deadly radiation.

The Inklas are similar to Phantom but for a different reason

It's a sign of weakness to take your helmet off

“…yay?”

The sign of weakness is hated in the Inkla clan/family/bloodline. Calling any of the weak, even if it's a joke is like spitting in their face

so i can’t just do this to one of them?

Their helmet is usually tight on the head, not tight enough to stop blood flow, but tight enough that it can't be removed easily

Since we’re talking about how the helmets work, I’m assuming Phantom wears a balaclava beneath his goggles and mask, and over those is his hood/helmet.

That's a f**king awesome diagram, and that's what I was thinking, balaclava, goggles, and then helmet. But I imagine his helmet to be advanced to have a built in fan and a easy way to eat and drink.