Aversion Staff:
Source: PHB3
Property: You gain a +2 item bonus to all defenses against attacks from enemies that are subject to effects caused by you.
Here's the specific item in question, as requested =)
Fantastic! Thank you very much!
What a dreadfully designed magic item!
Clarity comes from the section on Durations of the Rules Compendium (page 226), which begins as follows:
"Most effects in the game are instantaneous, as brief as a sword blow or a fiery explosion. Some effects last for a round or more, however. Such an effect has a duration, a specific amount of time that the effect lasts."
Overlapping effects? In summary:
* The effect that has the most time left supercedes the others.
* Effects that Save Ends are tracked separately (so if the monster is "slowed until end of your next turn" and "slowed (save ends)" it is affected by both for the purposes of the power.
* Identical effects that Save Ends - use the first one and ignore the latter (RC 228)
The use of effect is in the standard English manner (i.e. "Cause and Effect"), and so you can get great use of this if you're a warlock through your curse! Although it might be possible to argue that hit point damage is an effect that continues on the monster until healed, that way madness lies.
Is that clearer?
Cheers!