Board Thread:General Discussion/@comment-4383275-20160827054600/@comment-27907368-20160828061302

I'm going to reflect on your main post some before I have a major foot-in-mouth again; sometimes, I'm too eager to jump into things! :D Anyway, let's do this!

Anomaly Flowey
In short, the anomaly must be Flowey because Sans conducted his research before the player/protagonist entered the Underground.
 * Sans also believes that the protagonist is the anomaly, not the player.
 * He has no knowledge that SAVE ability transfers based on determination.

Reasonable Flowey
Flowey does very little; manipulating Papyrus is a small discretion considering that Flowey retains all memories unless a True Reset occurs.

He could have really impeded the protagonist if he wanted to. Instead, he watches and chooses to speak to/manipulate Papyrus time and again.

Flowey Doing What He Does, Writing Notes?
All right. So, the note in the trash can reads: It's almost certainly Flowey who wrote this accusatory note. (Please let me know if my logic is bad. :'D) Evidence includes:
 * (There's a message crumpled up in the trash can.)
 * (It's in a strange kind of handwriting.)
 * (It says...)
 * (I KNOW WHAT YOU DID.)
 * Papyrus's stilted phone call directing the protagonist to the Lab and collaboration with Flowey.
 * The note blackmailing Alphys to progress the plot (impeccable timing, very small time frame for it to get placed)
 * Flowey is one of the few (if only) characters that knows about the Amalgamates and has the motive to guilt Alphys.
 * Undyne, Papyrus, Toriel, and Asgore could not have written it.
 * The handwriting probably isn't Sans's, so he couldn't have written it either.