Because DoD's all about the traps. Summoning Trap: pulls in 2-3 monsters right next to you. Siren: all nearby monsters get a Monstrous Rage buff (even if a monster sets the trap off...) Grenade Gargoyle: shoots improvised explosives Swapper Stepper: left and right hand equipment switch. Left and right ring switch. Current HP and MP switch. Whoops, that last one's not so harmless... Outer God Peephole: hits target with Eldritch Inhabitation Trap Mimic: looks just like a trap until you get close to disarm it, then it attacks you.
I especially like the last item. Target those builds that walk through the level, Hoovering up all the traps without thinking about 'em.
One way teleport traps are always fun. So are one way trapdoors leading to the next level. Trapped chests would be fun too. "Idiotproof traps" would be an interesting addition. The higher someone's trap affinity the less likely they are to disarm or spot it.