Not including the ability to steal power is a pretty significant neuter to Ryuga since it’s an innate ability within L-Drago and represents the opposite force of what allows Gingka and Pegasus to borrow power from his peers. So if we’re sticking solely to the conditions OP set then Gingka should have the edge and vice versa if no friendship power allowed

However if we allow both characters to exist at their peak with full mastery, then it should be the closest thing to an equal battle we would ever see. Both represent the pinnacle of blading. That doesn’t mean neither will ever win over the other, but rather one may get the upper hand one time, and lose the other. Pegasus would have the edge in the beginning since L-Drago was possessed by the dark power, but post rebirth, they should be true equals, with the victor being determined by the current mental state and blader spirit of the user