I think that Nikos (alias "Nikosgranturismo" or "Nikosgranturismogt" or "Jules72120" or "Jules*": not clear!) wants to restore the asterisk at end of his preferred account name. But may be there are issues on Translatewiki.net with such asterisks, e.g. for tracking changes, or exporting data in various formats (not just for Wikimedia). But he made two different demands, and he should be consistant in his renaming demands (repeated now and alrady in the past!).
MediaWiki accepts the ASCII asterisk in their page names (including user pages, but this is an artefact as the real intend was to allow it in article names), but this is not true for all tools (not even in all tools used by Wikimedia, e.g. in Phabricator, or IRC, or Toollabs, or other CMS like Wordpress). Asterisks are not part of acceptable identifiers in programming language according to CLDR and Unicode character properties; they are rejected in many internet protocols (e.g. in the DNS for the start of authority and in the Whois database for domain owners). The same is true in many filesytems and applies to the question mark (?) which is also problematic. Choosing such user names with ASCII asterisks or question-marks in Wikimedia is definitely not recommended (even if it still works for now, there's a risk that in the future such possiblity will be refused and all these users will have to choose a better name, notably if this causes damaging security issues).
But Nikos should be aware that Translatewiki.net is not bound to Wikimedia rules and local user accounts are completely independant (and not linked with Wikimedia SUL for example). Renaming an account cannot be honored from an account that the user cannot authenticate with (this could be used for abuses and defamation of unrelated and legimate users, in,cluding in personal attacks to unfairly get someone being administratively blocked). Renaming may be needed in some cases for anonymization, in which case the demanding user will not be able to specify the anonymized account witll be be very generic with a common prefix and a random pattern at end (such as "Anonymous-9823141"). Renaming an account is costly in terms ofresources in the server as it involves global searches and edits in many pages, and there's not even a warranty that this will succeed everywhere (including many existing third-party mirrors).
There's then NO assumption (or requirement) that any account name will match between TWN and Wikimedia (and no reason to unlink/rename one account from one domain or another, if they were validly created and are still in use (this is also still true for many legacy accounts in Wikimedia that were registered separately with the same account name but by different users on different wikis, before SUL was implemented and deployed: such renaming requests are also rejected by Wikimedia if their existing owners are legitimate, and active or have made many of useful contributions, because this is required for respecting their respective copyrights and authorship).
No user should assume they have an universal right to reserve an account name on various domains they may want to subscribe and use separately in the future (or never...). However, as as the desired account name is available (and not used by any link, don't just look at the existence of the user page), users may just take these accounts themselves (with a new registration after logging off) and then alter their previous account using a local redirect (they can legitimately alter their previous user page if they logoff and logon again with their previous account). Such thing must not be abused: users should limit the number of account names they need and the only ultimate right is just the legitimate right to anonymize themself to protect their privacy, or the need to work with a separate identity to match a specific role (e.g. as an approved worker in an organization, or for operating a bot separately from the personal human interactions). This should not be used at all to avoid a blocking, or falsify votes: account creations by the same user should be limited
Hi Jules*, I have done the requested rename now. And excuse my mix-up with User:NikosLikomitros. For the future please open for every request a new thread. Thanks.