First, I have to say it's kind of nostalgic to hear this song today because like 5-6 years ago it was one of the most used in amv XD
Not bad all in all, but I really don't get why you used those two animes together, well in a way I didn't expect them to look so well together so it was a pretty original idea but when it comes to editing I think you didn't pull out all the strength of this mix. Indeed, it lacks of homogeneity, we have a part FMA then a part Fate Zero but they never really fuse together, I'm not saying you should have done a crossover but just find more links between the two animes and don't separate so much the two of them.
Except this point, it's not perfect either in the technical part, you use too much flash to mark your synchro and effects like cookie cutter (at 0:51 for example) should really be avoided 'cause they're not really clean, it overloads the image. Be careful also about the transition at 00:39, it's not clean either, nothing justifies this kind of transition so you should avoid it. Apart from that there are also some nice transi with masks etc. I think you've already some basis, your pace and synch' aren't bad either, just it can be improved, sometimes you don't mark synch enough, try to be more acurate with the sounds of your song.
Last but not least (well it's a detail in the end), 3:52 never do that again xD The same scene with those cam' moves, it looks plain wrong and it's a shame because it's the end of your amv, though it's noticeable you were getting tired of editing it in the last 30 seconds or so.
Anyways, it's not bad, you have some basis, if you correct your technical flaws I think you can rather quickly do nice amvs, so yeah keep it up! Good luck for the next!