Lightsworn said:
I would agree had Krilin actually asked that question "Are you ready to take on someone stronger than Freeza?" But he doesn't ask that. He says that Cell is more terrible than Freeza and asks if that scares him or not. It's said in a way that that someone before that had not surpassed Freeza. Saying "This thing is even stronger than that android you fought, does that excite you or scare you? Now that would make complete sense and would be the perfect way to hype up Cell. It would almost be like hyping up Beerus by saying he is even stronger than Cell instead of saying he is stronger than Boo. It just doesn't make much sense in the context of the whole situation.
If Kuririn actually asked directly "Are you ready to take on someone stronger than Freeza?" then yeah it's immediately a throwaway statement (that's what I got from your post, anyway). I wish Kuririn had been more direct with what he said, but he just wasn't. Plus, like I said, I'd have most likely agreed with Freeza > 19/20 had it not been for evidence on their side (e.g. 19 post's ability to draw blood from Vegeta, Piccolo's statement on 20 post) that leads me to reevaluate everything.
Lightsworn said:
Even if you want to take the word terrible to not just power, 19 and 20 are more terrible than Freeza anyway. 20 immediately tried to kill yamcha and they made it very clear they were planning on killing Goku and the Z fighters right away. Freeza toyed and never showed his full power until the very end.
I disagree. Freeza wanted planetary destruction and possibly universal domination. 20 wanted revenge on one person. We could go back and forth on this all day btw. It's subjective to us and it's subjective to the Z fighters, but since I've already explained why I find Kuririn talking about power straight-up to be weird, this is what I choose to go with instead.
I also said that it does have to be related to power to some extent or else Goku would have no reason to be afraid. Even if 19/20 were actually weaker than Freeza, asking "this guy's stronger than Freeza, does that scare/excite you?" is a pointless question anyway as I pointed out earlier: we already know the answer. Which is why I said that Kuririn is more saying that Cell's challenge to the current Z fighters will be worse than Freeza's challenge to the Z fighters on Namek. And he's right, seeing as how Goku could actually challenge Freeza back then, while no one can even challenge the androids, let alone a Cell who achieves his goal of becoming perfect.
Lightsworn said:
19 and 20 would logicallly be used to add effect to the dire situation by Tien, Kami, and Clearin because that would make the most sense. When you're trying to hype up how strong a villain is, you use the second strongest villain as a comparison naturally. What purpose is there to use a villain that is far weaker?
Your last question, again, would apply even if 19/20 were weaker than Freeza. Freeza is nothing right now. He was offed by Trunks in no time. Trunks was weaker than Goku. Goku trained for 3 years. It makes zero sense to ask Goku if he's ready for someone stronger than Freeza. Of course he is. The statement isn't a simple "Cell > Freeza, are you ready?" in my opinion.
As for Tien and Kami's statements. Tien was talking about Trunks, so he just brought up Trunks's last milestone. There is nothing else to compare Trunks to, all Trunks has done so far is kill Freeza. Same goes for Kami. Plus, saying something like "they beat even Vegeta who was able to beat 19" has little significance on the casual reader since 19 has pretty much always been a non-threat (given the time he showed vs. the time Freeza was at large). It's worth considering sometimes that Toriyama's not writing the story for power level freaks like us (I probably sound hypocritical as hell saying that but whatever).