I'm not going to write complaints for all the Knights of the Round Table, as Sirs Gareth and Gaheris have to be dead for Gawain's complaint to make any sense (and heaven knows something in this story has to), and I don't have enough information on Sir Palamedes to even come up with a complaint.
Requested by: ZenoZen
Current Client: Sir Percival
Irisviel: Hmm. Good thing I've got a box of tissues ready.
Percival: Ma'am?
Irisviel: Here, help yourself to these tissues. What seems to be the matter?
Percival: I don't know if I'm a good knight or not.
Irisviel: Oh, you poor man. Do explain.
Percival: I always thought I was the 'cream of the crop' when it came to being a Heroic Spirit, but I just figured out that so many of my brothers in arms are also considered the 'cream of the crop'. We're all the best, all the finest. I – I don't feel so special anymore.
Irisviel: Oh, get a hold of yourself. Being the best at something isn't all there is. You and your friends can celebrate each others'... um... awesomeness! You're the Knights of the Round Table! Divided you fall, but united you stand!
Percival: Isn't that the name of a song?
Irisviel: Yes. Yes, it is.
Percival: Well, I guess I feel a little better.
Irisviel: You should. The Knights of the Round Table are the best Heroic Spirits there are.
Percival: But what about Gilgamesh?
Irisviel: What? What about him?
Percival: Isn't he, like, the most powerful Heroic Spirit ever?
Irisviel: Oh, pish tush. Being powerful doesn't make him the best. Where's his sense of honor and chivalry, for one thing. I like you much better than that golden snake.
Percival: All right. Thanks.
Irisviel: Any time. Any time. All right, he's gone. Now I can finally eat that bag of gummy worms I've been saving... oh, mm, I've been needing this.
If anyone's wondering, the song is United We Stand, Divided We Fall by Two Steps From Hell.