Is it possible, and what would you guess are the chances to get loot twice in a row from it?
I have NEVER gotten loot twice in a row from a seal. However, I always get loot by the 3rd try, so the bad luck protection must be quite strong. If I had to guess, I would say your chances of getting loot again after successfully getting loot from a roll is 0-15%, second try is 25-50% and third has to be 80-100%.
for the last month, I have been using most of my coins on Guldan trying to get Druaght of Souls, is it worth it to kill him 3-4X a week and use 3-4 coins, or should I stop after successfully rolling and getting loot? Again, I have NEVER rolled loot 2X in a row, but it could be the same poor RNG that is stopping me from getting the trinket in the first place.