[Suzerain of Sheol]

Hmm. The only thing I can think of why Borderlands would be that hard is because of thee RPG elements. Despite looking like a shooter, it really is an RPG and if you get unlucky with weapon drops, it can make it really hard to deal with the enemies. Plus, some enemies require certain types of weapons to take down easily and if you don't get a good one to drop, it can make it really miserable trying to get through.

As for Halo, despite playing the second game nearly to death (only one I ever played) I can barely remember anything about that series.