Tales of Vesperia

Actually that isn't true. I have done the hundred man melee without Flynn or the hunting blades. You have to beat the thirty, fifty and eighty man melees first before you can attempt the hundred. Not sure the earliest you can try it but you don't need all the letters of challenge.

I can corroborate sirian hawk on this one; i have indeed unlocked the 100 man melee without those letters of challenge. i'm trying to figure out how to get into the 200 man melee right now... maybe they have something to do with that...?

You can go to 100 man melee without the letters but then you won't be fighting any cameos. But to unlock 100 man melee, you have to go to Ehmed hill and look around until theres a cutscene and then Mt. Temza and then go to this port (forgot which one)

I can confirm with Knox all you trully need is the leviathens claw invite to get the 100 man melee. The other two invitets are for the 200 melee.

The letters are needed to a degree. 100-man melee is unlocked by obtaining the Leviathan's letter, HOWEVER You cannot obtain the 100-man melee true prizes unless you have all three. Without them you will obtain a gel set or a herb set or something. With all three you get unique items, usually weapons, when you beat 100-man melee.

Sorry I miswrote that. It isn't Leviathans's letter, it's any one of the three. My bad.

You need to do the 100-man with 3 people -all 3 letters- in order to unlock the 200 man melee along with completing the EX Dungeon

Actually you can go to fight ing the 100 man melee after u go 2 mt temze looking for judith but u have 2 beat 30,60, and 80 man melee b4 u can fight in 100 man melee (also a 200 man melee after ex dungeon)

Right.... To actually answer your question, you have to go o Torim and head near the docks. You'll find a scene with Gauche and Droite, and an orphanage. After you get that scene, got to Zaude and work your way in until you reach the place where you fought Yager. You will have a fight with the two, and after winning will earn the letter.

Three letters are needed to get the good prizes out of the 100 man melee. There is a 200 man melee as well. For that, you must have beaten the 100 man with three characters at least, then beat the last boss of the EX dungeon for a fourth letter. The 200-man melee will now be unlocked.

Hope that clears things up for ya.