As you're all aware, Brave Frontier's metagame focuses on one thing primarily: maintaining BB and SBB gauges for BB spam. However, this focus in the metagame makes challenges such as trials far less interesting. Even though this will probably never reach Alim, it's still fun to talk about, so what are some ways dungeons could be designed to diversify gameplay?
 
Here are my ideas for bosses:
* BC-drop resistance on bosses (though still doesn't stop Matah-style teams)
* Every turn, the boss targets all units with full SBB gauges with a powerful, buff-removing attack. This would mean regular BB's have a use again, and generating tons of BC may no longer be ideal. You'd have to balance between generating enough BC to BB but not enough to SBB. This would also give units which max at 5*s a chance to shine
* Bosses with some sort of "Anger point," which every third turn or something requires you to use regular attacks or take massive damage
* Dungeons restricting you to 3 units
* Dungeons banning a certain element or elements in your units
* Dungeons which don't allow BB/SBB (except maybe on your lead/friend?)
* Dungeons which disable LS
* Dungeons which disable HC drops
* Dungeons which only allow non-RS units (and maybe also bans Karl, Grah, Maxwell, Cardes)  
What can you guys think of?