Board Thread:General Discussion/@comment-26006155-20190820122909/@comment-26907577-20191004180541

Jumping around:

"Alpha Sans, now cursed with darkness in his soul, no longer has the innocence neccessary to get the best ending. So he resolves to help his earlier, more innocent self (Frisk) get a better ending by posing as guards by the Ruins Door, then giving Frisk as much aid as he can along his trip without blowing his cover as being a human trying to help another human."

Well, why can't he get the best ending? Let's consider the requirements to get the best ending:
 * Flowey sneaks past Asgore and absorbs six human SOULs.
 * Almost every monster is also present.
 * Flowey is SAVED and convinced to break the barrier.

Now, if Sans were to reveal his humanity, then it would be easy for him to distract Asgore long enough for option 1.

Wait wait wait.

Hold up.

Hold waaaaaay up.
 * 1) Flowey has fought Sans before.
 * 2) Flowey hasn't been unable to SAVE before.
 * 3) You claim that Sans is Frisk.
 * 4) Frisk is able to prevent Flowey from SAVING.
 * 5) Per 1 and 2, Sans has not been able to prevent Flowey from SAVING before.
 * 6) Per 3 and 5, Alpha Frisk isn't able to prevent Flowey from SAVING.
 * 7) Per 4 and 6, a contradiction.