Domain names have to be a subset of ASCII, so you have to use a Latin script. However, you could use Punycode to represent non-ASCII Unicode characters, if they do not somehow prohibit that, I suppose.
As far as I can see from the developer documentation [0], the domains resolve to a set of blockchain addresses and some meta-information about the owner. Using this for email would be non-trivial, especially considering it's an alternate root and thus is not supported by any major email provider that I know of.
Unstoppable, unless you try to register in anything other than Latin script (the rest of the world exists, you know!)