I don't want to call this a design flaw, but I just strolled through three levels in the 6th stratum (levels 24-28) using nothing but the Dark Briar Barrage (the 5* Snarbolax bomb). These were wolver levels, and the piercing damage of the bomb just destroys these clueless mutts. (It works great in Deconstruction zones on gremlins as well.) Soloing in the 6th stratum should just not be so easy it borders on boring. Also, the game seemed to play so much easier solo as well - less aggressive pursuit tactics by monsters and such. But how did I solo through the entire tier 3 and not pick up a single 5* mat?!? C'mon, design guys! (The other essential weapon is the Argent Peacemaker for firing through mist screens and general speed and damage, and I also roll with the Divine Avenger and Leviathan for battling big, bad Jellys.)