Yes Tyler ,
I agree, I tried to use this domain in other hosting, but I removed it.
And pointed nameservers of this domain to
ns1.hstn.me
ns2.hstn.me
Also, I deleted my account and tried to create a new account in aeonfree.
Then I am seeing this issue, not able to create new account with this domain.
UPASAK.XYZ IS NOT AVAILABLE
We provide you a free subdomain for your hosting account. Also, You can add other subdomains from control panel later.