Username with changed...

[Callid]

CCllii.

Replace every letter with the letter it represents on the keyboard if mirrored along the line Z-G-V (i.e. E becomes O and vice versa, S becomes K and vice versa, G stays G and so on.

[breva]

vuobl

Like that?

Add "Yuki-" at the beginning of you username

[Callid]

Yuki-Callid

Nah, it should have been ciovl. I just realized that the line would have been Y-G-V for you, as you're using an American keyboard. On a German one, Z and Y are swapped

Replace every vowel with "ara" / "ere" / "iri" etc.

[Hoshi, tantei-chan]

Horoshiri, tarantereiri-charan

Add -chan/-kun at the end of your name.

[Callid]

Callid-kun

Replace every vowel with "ara" / "ere" / "iri" etc, but if two vowels follow immediately after each other, only insert an "r" in between.

[Hoshi, tantei-chan]

Horoshiri, taranteri-charan

Type 'dame' before your username  (sorry, just wanted to see)

[Callid]

dameCallid

Remove all blanks and/or punctuation marks and insert a blank after each third letter afterwards.

[Hoshi, tantei-chan]

Hos hit ant eic han

Ne, Callid, have you watched 'Reborn!'?

Write your name in any type of code

[Callid]

I suppose you meant a cipher, as "writing one word in code" makes no sense at all.

smitcv (Used chiffre: One-Time-Pad)

Write your name using a different font for each character (no repetition!).

[sstimson]

sstimson

Fun ( not )
next username but upside down or rotate 180

[Callid]

C^_É

[sstimson]

S T M O
S I  S  N = Stmosisn

Simple next one username with if you can chess symbol next to it

mine would be sstimson

[Callid]

Callid K

I'm interested if anyone can actually display DiagramTTHabsburg

Write you name in Windings!

[Cheesus]

ï

[KainTheVampire]

KeinTheVampira

Looks kind of odd XD

Write your username without consonants