Goddess Rhongomyniad a.k.a. Lion King is from a history in which Bedivere never returned Excalibur to the Lady of the Lake, preventing Artoria from passing on. As a result, Rhongomyniad has changed her greatly, completely transforming her into a Divine Spirit, the Goddess Rhongomyniad.
Hassans power was directly compared to lion King by gawain who has seen both in action/seen them both fight separately.
Keep in mind that First Hassan is a Grand Servant.
Along with her being compared to a grand servant like Hassan, it's stated her spirit origin output far surpasses the original king Arthur aka Artoria, and she reached a realm that's above any normal servant like how a grand servant is 1 rank above every normal servant.
Her power output is above space time she was able to strike with so much power it was able to be felt in Chaldea which exists in the future, blowing pieces of SHEBA away (Chaldea may exist outside of the time-axis, though I'm not sure abt that).
No normal servant can stand up against her authority.
Her Noble Phantasm Rhongomyniad’s magical energy was estimated to have a power output of 3,000,000. A "high-ranking" NP would be an A ranking one, like Achilles' Troias Tragōidia. Someone like Ciel (Remake) has 5000 Magical Energy.
Rhongomyniad on its own is even stated to not be any weaker than Excalibur.
The burns left by Lion King’s judgement were promptly compared to Goetia’s burning bands of light as well. Albeit Chaldea had yet to experience the latter firsthand.
It is also at least on par with Ivan’s attacks,
Rhongomyniad is also stated to be on par with Surtr (or Loptr Laegjarn).
When fired by Morgan towards the Atlantic Lostbelt, Wodime was forced to use his full power in order to block Rhongomyniad, and was going to destroy the Lostbelt regardless of what Wodime had planned, including killing Zeus in the process.
Therefore, I change my take. Goddess Rhongomyniad should be superior to Artoria Pendragon (Fate/stay night).
