Dropped about 50 souls and managed to pull US Eddie and the Major! Haven't bought event souls for ages due to the odds; only invested in these for the Trooper frags (got about 1450 total now). I was going to slowly use them grinding though the Trooper Dungeon but seeing as I lucked out opening the souls I'm tempted to forget about the Dungeon and the achievements and just cash in the Trooper souls for the Frontier Coins and sac value. Only thing tempting me to do the dungeon is the Talis... I've found 3 so far from about 20 runs so odds of those seem pretty good at the moment.