He claims he is “God” but reading into the article it is clear he is not the creator of the universe as he claims.
https://scp-wiki.wikidot.com/scp-343
SPOILER
SCP-343 is possibly a powerful reality bender as his cell is larger on the inside than the outside, he deletes records and creates false ones, and he seems to be able to manipulate guards as all abandon their post and allow anyone access to him.
What really is SCP-343 and what does he truly want?
I like a lot this character, especially his “turn around way” to answer any question
Top 26 Questions To Ask SCP-343