Anyway, I am going to list some feats for the series.
Firstly, Dracula is the Lord of Darkness, but what exactly does that title mean?
Dawn of Sorrow explains:

Castlevania Dawn of Sorrow Walkthrough (Meeting The Cult & Balore Pt. 4)
"For God to be perfectly good, there must be a being of perfect darkness."

Castlevania Dawn of Sorrow Walkthrough (Menance Pt. 31)
"What Celia told you wasn't necessarily wrong. The Dark Lord is the entity opposite to God."
The Lord of Darkness is the entity responsible for all evil, serving as he antithesis to God's goodness.
Now for feats:

Castlevania Harmony of Dissonance Full game playthrough-0
At 43:13.
Dracula, as a shattered spirit possessing Maxim, created the second Castle dimension, and said dimension contains another moon. Dracula while in full power, has two 4-A feats:

Castlevania Bloodlines Final Boss (Eric) Dracula - No Damage, No Subweapons, No Power Up
First is him creating a pocket dimension full of stars in the background during his fight in Castlevania: Bloodlines.

Castlevania The Dracula X Chronicles Stage 8 - Bloodlines
And the second is Dracula creating another pocket dimension upon transforming, this time with a visible Black Hole in the background sucking up stars.
Finally, we must understand the God-Tier of the franchise: Chaos.

Castlevania aria of sorrow full game playthrough
At 1:29:00.
"The evil in this spirit comes from those who seek Chaos and destruction. So we need to cut off the source of the Chaos influencing the spirit."
"This castle is a product of Dracula's magic. It's a spiritual world. My point is this... A stream of Chaos exists within this castle as well. There is a place where only you, Dracula, can go. That's where the Chaos is!"
His enemy description in the bestiary is:
"The Source of all chaotic things."
This is the only information on Chaos we get during Aria of Sorrow. Thankfully, the
Akumajou Dracula: Kabuchi no Tsuisoukyoku Light Novel gives a lot more information. Some relevant quotes:
"The castle is the symbol of the chaos within humans and as long as people exist, it will not be completely sealed."
"As expected of the castle's guard, the devil's confidant, born from chaos as a god of death while being undead."
"As I've said, I would equally gain control over the human world and the source of Dracula's power, chaos. I do not intend to obey someone else's mind aside from my own. That includes you who were born out of chaos."
"If I could control the even heart that is the root of humans……Would the chaos that is born from them no longer exist? I have no interest in tranquility but it could be fun to challenge that."
""A person that can shoulder the call of chaos is appropriate to continue Dracula's name----- The one that inherits his name and power as the lord of this entire castle, will forever be my master."
To summarize, Chaos is an entity born out of the Chaos in all humans, and acts as the source of all evil, demons and chaotic things. Dracula, Death, Dracula's Demon Castle, all of them draw power from Chaos and can be cosidered manifestations. In other words, it is the true Anti-God of the series.
Chaos resides within his own dimension,
The Chaotic Realm, take a look:

Castlevania Aria Of Sorrow Episode 31 Entering chaos
As you can see, the Chaotic Realm is filled with both stars and galaxies swaying and spinning in it, and this is done through Chaos' own power. This is not only a 3-B feat in potency, but also a MFTL+ feat in speed. This would scale to Soma Cruz and Julius Belmont.
A Final Tally would look like this:
Dracula: 5-C or
5-A (Created a dimension containing another Earth and Moon) |
4-A (Can create dimensions filled with stars, and Black Holes which devour said stars)
Soma Cruz: 3-B (Fought against and defeated Chaos, who is the Antithesis to God, and the source of all evil, chaos and demons, who exists in the Chaotic Realm where numerous stars and galaxies are constantly spinning as a result of his power)