What are the odds of getting El Patron's Sword?

[Kid Heartbreaker]

I got mine after beating Darkheart somewhere between 250 ~ 300 times (I was part of a 5 person group at the time and the only one to get it).

I tend to agree with the idea of a Group being better because it seemed someone in the group got something decent from the Chest drops.

There is a huge amount of random luck involved too. For several "Group Rounds" I just had out the Staff for the healing of the group and only did the basic blast on the enemy 1 or 2 times and still got decent drops as well as the lesser gold and really nice Puffy White Shirt.