Some notes about Mirai...
In his human form, he is completely human in all respects - he has all the same organs, all the same body parts, and they all work the same, with no sign that he is actually an alien being. Individuals who can sense unusual energies, however, would pick up an odd 'emanation' from him, that being the Light Energy that powers him as Ultraman Mobius. Most people can't sense this... but most people aren't going to be at Milliways.
His transformation device, the Mobius Brace, is normally shunted just a little into an energy state, and is invisible and intangible until he summons it to transform.
Based on parts of the series, and the movie, Mirai has learned (from Ultraman and Ultraseven) the trick of transforming without growing, but still has that pesky three-minute timespan to act before dying.
...yeah, see, that's why he spends most of his time as Mirai instead of Mobius. There's a bunch of different reasons why given in the series, everything from the natural light filtration of Earth's atmosphere, to pollution in the air, to the spiritual pollution of Earth, but an Ultraman can only act in an Earth-like place for three minutes before dying. About a minute and a half beforehand, the light on their chest will start to blink, showing that their energy is getting low. It will blink faster as it becomes more dangerous to continue, and when it goes dark, the Ultraman dies. This isn't the end - the Space Garrison has ways it can bring a dead Ultraman back - but they aren't guaranteed to work.
There can also be a 'recharge' done, but that only will reset the timer up to three minutes. (This is most dramatically done in the Ultraman Mobius and Ultra Brothers movie, where Ultraman Taro and Ultra Commander Zoffy appear and recharge the Ultra Brothers, all on the verge of death, with beams of light.)
If you have other questions, please feel free to ask here, and I will answer them as best I can.
SHUWATCH!
His transformation device, the Mobius Brace, is normally shunted just a little into an energy state, and is invisible and intangible until he summons it to transform.
Based on parts of the series, and the movie, Mirai has learned (from Ultraman and Ultraseven) the trick of transforming without growing, but still has that pesky three-minute timespan to act before dying.
...yeah, see, that's why he spends most of his time as Mirai instead of Mobius. There's a bunch of different reasons why given in the series, everything from the natural light filtration of Earth's atmosphere, to pollution in the air, to the spiritual pollution of Earth, but an Ultraman can only act in an Earth-like place for three minutes before dying. About a minute and a half beforehand, the light on their chest will start to blink, showing that their energy is getting low. It will blink faster as it becomes more dangerous to continue, and when it goes dark, the Ultraman dies. This isn't the end - the Space Garrison has ways it can bring a dead Ultraman back - but they aren't guaranteed to work.
There can also be a 'recharge' done, but that only will reset the timer up to three minutes. (This is most dramatically done in the Ultraman Mobius and Ultra Brothers movie, where Ultraman Taro and Ultra Commander Zoffy appear and recharge the Ultra Brothers, all on the verge of death, with beams of light.)
If you have other questions, please feel free to ask here, and I will answer them as best I can.
SHUWATCH!