Def, bridging my head voice has been the high hurdle in my singing education thus far.
As for Akuma,
I'd suggest doing lip roll exercises, these tend to make it easier to hit head voice and can make you understand where your breaking point is. Check youtube on "lip rolls" and it should come up fairly fast. And Yeah, all those bands are from people that are very comfortable and have the ability to hit notes in that register.
I remember trying to sing all those kind of bands when i was first starting singing, let me tell you, it's never good to strain your voice to hit notes, work on it...keep it going, do at least a half hour of warm ups before singing and reduce intake on dairy. Dairy is a large mucus generator and can reduce the tone in your vocal registers.