So let's talk resurrection-
Whether it's D&D or Mutants and Masterminds, eventually the characters die. Some of them come back from the dead due to regeneration (wolverine style) and you can argue that they never actually "died"- while some come back like a vampire.
The process as described in D&D (who knows what's happening in M&M since you can make your own deific cosmology) is that the body is repaired (or re-made) and the soul pushed back into it. Some systems call this jarring for the soul and put the negative level in there as part of that. Mutants doesn't do that, but you could still be calling your soul back from beyond.
But what if your soul is still alive, or if you have 2 souls left to recall?
Since the system allows for time travel (or dimension travel) this is quite possible.
Consider the following:
1) PC goes back in time 10 years. (At age 20). From 2010 to 2000.
2) PC exists in 2000 as a 10 year old (his past self) and as a time travelling 20 year old (his current self).
3) 20 year old PC dies.
4) A resurrection magic is attempted.
What happens?
One might argue since there are 2 souls out there, only one of which is dead, the resurrection goes off with no problems. One might also say that the "closest" soul is that of your 10 year old self, which is not eligible for resurrection, so the spell fails. Consider that you cut your body in half for example- you can't resurrect both halves. But why not?
Well, let's assume that the 2 souls are separate entities. What if both the 10 year old and 20 year old die? You might say "Well, the 10 year old dies so the 20 year old vanishes", but we see from back to the future that as long as time travelers are still there to "fix things" then there may be a delay in the older one vanishing. (Futurama even allowed Fry to become his own grandfather after killing his grandfather in the past).
In any case- which one returns? The old version, or the young version?
Well, let's assume that the young self resurrects in the young body first, then you cast on the old (who is now eligible due to no timeline messing).
Well, what about alternate dimensions? You are going on a sliders style campaign. You enter an alternate dimension with another version of you (not a temporal version, but an alternate version). You both die. Who gets resurrected? The DNA is the same, the "soul" is the same (with different experiences, but the same energy). You might make an argument about the body, but then some resurrection spells don't require the body (and the DNA is the same anyway).
Okay, let's take this further:
Bob goes 20 years into the future. (Time travel- not "the long way"). From 2010 to 2020.
In 2015, recognizing that there is no Bob- resurrection magic is attempted. Does it work? Why not? There is no Bob? You might say that he has no soul here (since the soul went with him). If resurrection just restores a body and there is no "soul", then what happens in 5 more years when the guy shows up from the past?
What if a character dies in 2010, is resurrected in 2015, then goes back to 2013 and attempts resurrection? Will it work? Is there a spare soul floating around out there?
Next step- spells like Clone. In D&D, the clone spell is basically a prepared resurrection where your soul goes back into your body once you die. The clone stays "dead" until your regular body dies, then your soul inhabits it.
What if you cast this spell on an alternate dimension where there are 2 of you. Will it immediately animate with your alternate version?
So many questions- no real answers...
