Ritsuka is a hero who always does what he can to save the day. He’s even honed his body so he can at least try to fight a bit on his own without the aid of a Servant. That’s not enough against Bass though. If he fires off his Earthbreaker then there isn’t going to be much that Ritsuka can do to counter him. Ritsuka probably won’t even be able to see Bass due to the difference in speed which will work against him here. You can’t beat what you can’t see. Bass wins.