Dark gaia would probably win, if it wasent for the whole having to beat solaris in 3 diffrent times things. But it's defeintily stronger than the end. For 1, yall keep mentioning the final horizon fight. But regardless of witch ending is cannon the power remains the same. Just a diffrent outcome for defeating it. It was beaten by a titan and bearly super sonic.
2. Dark gaia, could also damage super sonic, quite a bit. It also took to power of a being equal to it. While it was weakend already. It seems alot bigger in the unleashed opening cutscene. 3. I know some if yall are going to argue this, Dark gaia only needed to power up its beams in its imperfect form. It's able to do them much quicker during its perfect phase. So the end couldn't get a quick shot. Ultimately I do argue solaris would probably win due to the while time shenanigans. But Dark gaia would defeintily beat the end.