The small yellow damage numbers (not the orange) that are hitting for 14k to almost 20k damage is the gem effect. You can see how many of those are flying around and how quickly, plus they can even crit! Gloom Cask can work very well even at Rank 1 (unlike most 5 star gems) but not sure I would recommend that in practice. I'm only using 1 buff source of attack speed here. The description has more information. The new 2 star gem is extremely powerful also, maybe one of the best gems out there now. Any questions leave them in the comments, appreciate it! Thanks for your time!