For competitive play, both are pretty important. Ideally, an adamant / jolly nature is suitable for Gyarados. Adamant raising attack, jolly raising speed
From an exclusivity standpoint, I don't think its necessarily a bad thing to offer the chance to the top guilds, to acquire certain forms...seems reasonable. They're at the top for a reason, and the work involved deserves some reward IMO
Just a few chats back in game was chatting to someone who had a poke I was interested in, now they're gone and can't remember their username. Can you tell me who I was chatting to?