How about some Coliseum PvE?

[Kosmos992k]

I imagine it'd in Ul'Dah if anything. Gotta make use of the coliseum.

Yeah, I was thinking in terms of re-activating the Coliseum in Ul'Dah, the idea of fighting the beasts of Eorzea in a gladiatorial arena reminds me of the Roman Colosseum.

How about inside a place you can actually customize and build and challenge other players to?

Customize then duel other people in the open world (other people can watch.)

Sounds like a great expansion of the idea into smaller custom arenas, would make a nice phase 2...

Sounds like a good idea to me too. Maybe have difficulty settings with scaling rewards upon completion instead of random difficulties.

They could limit usage with tieing it to leve allowance which would give a use for them at max level.

Mmm, yes, thats a good idea, it would naturally limit itself based on player allowance use.

Plus there should be a few quests with a story that shows us the lore of the coliseum in order to 'enable' the Coliseum for use.

well we do have the gold saucer. That would be a great place to implement such an idea as they have done it before in FF7.

I think the minion arena fights will be at the saucer and they fit the more whimsical feel of that place, I was thinking that this would fit the coliseum in Ul'Dah better.

I can see players spending hours on time trials and the like for this. So, solid and addictive idea.
Chock it full of humor, like that cheating pirate in the Maelstrom Lower La Noscea windmills, and other fun commentary between trials and people will grind it for months to get all the dialogue quotes.

Unfortunately, I also see SCH and WAR dream team duos on the top charts too.

Time trials, yes that would be great and another leaderboard is born. Adding in humor and 'color commentary' would add a lot of fun similar to the off beat humor in the Ratchet and Clank games.

If it is challenging enough, why not.
Randomly generated content has the higher replayability, atleast in my opinion.

Indeed, the replayability depends on making this challenging, and scaling the challenge overtime so that as players gain power, they get further in to the fights and as they do the difficulty escalates until it's too mucj.