Below is a description of a Detect Evil ability for the D&D Next Paladin. My understanding of Next is that it won't be reliant on alignment for mechanics so I have taken the ability back to a 2nd ed AD&D style. Please tell me what you think. Is it broken, badly worded, too complex. Tell me how you would alter it while keeping the intention to only detect hostile intentions rather than evil NPCs. Sorry for the wall of text that it is.
At first level, a paladin gains an aura that extends in a 30 foot circle around them. This aura penetrates through barriers, but 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt blocks it.
Every paladin no matter what calling they adhere to benefit from excellent awareness thanks to their aura. You can feel the hostile intentions of creatures within the area of your aura. The more hostile a creatures intentions the more aware you are of such hostility. When a person tells you a lie you feel only a slightly disturbing affect such as the palms of your hands beginning to itch. A creature wishing to hurt you might cause you real discomfort in the form of an ache in your chest.
While you automatically become aware that there is a creature within your aura hostile towards you, the direction & location of that creature is not readily apparent without taking an action to focus your attention on the feelings of hostility. As an action you may expend a use of your channel divinity to focus in on a feeling of hostility. If the creature with hostile intentions towards you is visible to you that creature is identified as the one emanating the feelings of hostility you have focused on. This focus does not tell you what hostile intentions the creature has (but you may guess based on the severity of discomfort you feel due its intentions). Your awareness of hostile intentions towards you does not tell you if the creature has hostile intentions for a friend or a companion of yours. You do not gain information about the ethics or alignment of creatures through this ability.
Some creatures are so hostile by nature that you are always aware of them when they are inside your aura. Fiends and Undead are immediately identifiable by you as fiendish or undead when they enter your aura. Depending on your alignment, religion, philosophy, or pathos the DM may decide that other creatures are always hostile towards you and you become immediately aware of them.
Paladins trained in the Sense Motive skill can learn to combine the knowledge gained by way of their aura with their trained insight into the motives of creatures. Any attempt a paladin makes to detect if a creature is lying to him may benefit from advantage at the DM’s discretion. (This could also be a great skill trick if those become available to all classes)