here's a few bugs / glitches that where a bit helpful while grinding some of the solo-missions
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in the first solo-mission you can shortcut the dungeon, at the place where the floor collapses, sending you falling to the lower level. You have to have done this mission at least once, to know the layout and location of the "trap". just before walking unto it, move as close to the left wall as possible, and thus walk towards the next door. at the moment the floor collapses you should have reached one of the pillar-thingies coming out of the walls, you will clip through this most of the time, reaching the other side.
Note this will rob you of the xp to be made from the mobs below, but if you just grind the mission for the reward, this saves you some time.
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During the first solo-missions bossfight, if your attacks have the slightest knockback ( as f ex rogues ) Baal will not fight back, just take hits and die.
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Just Advice, no bug / glitch
During the second mission, forgot the name, the one where you are assigned the noble task of rescuing a princess

, you will always want to take the left way, at the T-junction halfway through the dungeon. This will allow you to ignore most of the things that spawn to the right...(sounds dumb, but actually a few of the still come looking for you)
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Still during the rescue mission:
when reaching the princess, a cutscene will start. If you target the Boss in there before, and attack him, you will beat his brains out while he just stands there helpless ( during the cutscene thingie) porbably killing him without him being able to survive the scenes duration.
This also works for every part of the game where a "cutscene" is triggered.