There's no denying that this is an interesting submission, and that new things are showcased. After all, you're demonstrating save corruption/borrowing/why are you stealing from save points (and game modes), and as a result of that, Alucard is able to take new routes through the castle. All of that is impressive technically and entertaining visually.
However, the question being asked of this run is one of speed (the objective criteria by which runs are measured), and the fundamental criteria here is that the run is slower than using Maria alone. If Maria + Alucard is slower than Maria alone, why bother using Alucard in the first place? This is a slower run than it should be (by using Maria alone) because of how we time runs. If we were using SRA timing, there is no doubt there would be a leaderboard for this category, timed from whenever you gain control of Alucard, and this run would be receiving accolades, stars, moons, publications, awards, and all of that. However, because we time things from the instant of console power on until final input, the site can't just create a new category for this which follows its own non-standard rules, especially when a faster run (of Maria alone) exists. And when faster Alucard runs (that abuse game glitches) exist.
The closest parallel to this run that I am aware of to the RTA speedrunner world is EarthBound, Pajama%
. To set that up, you have to play through a significant portion of the game, then save, reset, shenanigans, and Ness gets to stay in his PJs for the entire game (well, until the ending. You know how EarthBound gets). Those runs are timed from when you start the glitch, not when you start creating save files to switch between. In that scenario, only Alucard's portion of the game would be timed, and that would be leaderboard-worthy.
This run, while impressive to watch, and which definitely deserves to be showcased, might belong on a YouTube channel instead of this site, because of all of the rules that exist here surrounding timing. It's a good run. It looks nice. It looks fun. It looks interesting. It doesn't follow the rules. Please showcase it somewhere. Link to it from your user page. Record the information about the glitch on the relevant game resources page. Keep exploring it, maybe something publishable will come out of it.