Actually, it is possible to solo the game with virtually any class (pure, dual, or multi) without cheating and removing exp. cap. I believe the trick is to learn how to use your class to the full extent and preferably to play the game at least once before so that most items and quests are familiar. After that it becomes easy (the first dungeon is probably the most difficult thing). In fact, some battles that were a nightmare with a group, took me much less time with solo player.
Mishik
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Mishik's Place