I have yet to encounter an item or a "spell" that allows me to resurrect foes (meaning allies?).
You actually get one for lucas at level 39. http://walkthrough.starmen.net/mother3/psilist.php I found this pretty useful while playing through. There is also an item you get pretty often called life noodles that resurrects allies.
Anyway, I finished the game a few days ago and have had a while to collect my thoughts. So here we go:
At first I struggled to decide if I liked Mother 2 or Mother 3 more. Actually up to about halfway through the game I was leaning towards the former. However, as the game progressed I found that I liked the sequel more. This decision mainly had to do with the story. I love the lighthearted feel and the charm of Earthbound, but it never really progresses any further than that. Before I played Mother 3 I actually though that a serious story would be detrimental to that lighthearted feel that I loved so much. I actually found it to be the exact opposite. I believe that they complement each other very well in the way they are handled in Mother 3 and that it made the overall game more enjoyable. Mother 3 also throws in some nice ties to Earthbound at the end although for most of the game they seem unrelated. Mother 3 also has a very creative end sequence before the credits which I thought was really interesting.
Another thought I have had is how in many ways the design of Mother 3 is similar to that of Final Fantasy 13. I, like Lindy and Jonny on RFN, have been playing through that game recently. I started to notice after I went through Mother 3 that the game is very linear, like FF13. But Mother 3 does a much better job of hiding this fact and makes you feel like you are able to explore more openly. If you ever do go too far off course, text pops up in Mother 3 saying “there are ants by your feet, don’t step on them” or something to that effect. Mother 3 feels much more open because they guide you from area to area without showing you that you are going in a straight line like FF13 does. The setup is the same for both games, really. Chapter starts, then a cutscene, then you play though an area. Rinse and repeat. The design of the two games eventually splits because it seems like at some point the developers felt a need to open 13 up, which is very disorienting when it happens and has turned me off from going back into it for now (I would have actually been fine with the game sticking to its prior format). Mother 3 doesn’t do this and really doesn’t suffer from it at all. I never once thought of the game’s underlying linearity while I was playing it.
And one more note, I found it hilarious that at one point in chapter 8 text from Leder popped up in my game and said “you have been playing for a long time, why don’t you take a rest” or something like that. It seems like Nintendo has been up to this kind of stuff much longer than recently.