Wouldn't it be nice to see a contest for co-op points in the Mystic Ruins? I think players that lead their teams in co-op points should get special prizes like diamonds, orange items, soulstones, or maybe diamond chest tickets. Maybe the highest ranked players on the server leaderboard get even bigger rewards at the end of each week. This might give players incentive to be more active.

I don't like, the optimal (for all to earn more items) is that the player who invites a ruins mystic doesn't complete any of the 3 stages, and if you are invited you should only help a guildmate once, because if you get invited 5 times and you "help" 5 guildmates clearing a stage of mystic ruins, then you will receive items only once, so 4 people that could have received items will get nothing. So actually you help more to your guild doing just 1 mystic ruins per day.

I agree, you explained the current set up and it does not benefit members as much. I'm proposing a change to the set up where collective points for everyone that helps earns rewards. The more points you gain you get rewarded for. I think that would be fair because right now, like you said, players are helping a lot and getting nothing for it.