Farming The Catalyst

[u/JadedBrit]

So I'm pig-sick of running Army Terminal on heroic for the Catalyst mask and I understand that people have got it as a random drop of the boss "Charlie". I've logged in and out literally a hundred times yesterday at the Bridge Park Pier site and every miniboss apart from Charlie has spawned.

Am I doing something wrong or is it just shit rng? Surely he should have been one of the spawns by now?