A flame that cannot be put out, it can only die when it doesn't have fuel.
This kind of sounds like normal fire? Or maybe some chemical-based combustion reactions?
At that point it will cause a large explosion, powerful enough to vaporize steel beams.
I feel like this is a meme reference. Also, if it dies, then isn't there no more anomaly?
A shadow that replaces a persons normal shadow and slowly leeches the victims life away.
Pretty generic horror story/videogame premise. I suggest reading over this essay on common SCP pitfalls to get an idea of what elements to avoid putting in an SCP article.
Literally anime, written as if were a disease.
We see this posted and deleted a few times a year. Never really works, since there are actually some really great anime out there, plus there are people who have never heard of anime before. Not really a universal enough joke to be made here that hasn't been spoofed by the rest of the internet already.
Out of curiosity, how many recently posted SCPs have you read? These seem like ideas that miiiiiiiiiight have worked 10-11 years ago, but aren't really up to today's audience's expectations.