10. Thou Shalt Bother To Explain The Infinity Stones In Proper Detail
There is no denying the fact that the mythology surrounding the Infinity Stones within the MCU has been mostly confusing thus far; Marvel fans know that these strange and powerful artefacts are set to play a huge part in future events, of course, but to date they have only been rendered as vague and interchangeable MacGuffins. The best explanation as to "what" these MacGuffins are - or what they're capable of - comes from Guardians of the Galaxy, when the Collector explains as follows:
"Oh, my new friends, before creation itself, there were six singularities, then the universe exploded into existence and the remnants of this system were forged into concentrated ingots... Infinity Stones."
And that's all has really been established: there are six of them, they are powerful, and forged as one they are infinity amazing. Oh, and Thanos - an intergalactic bad guy - wants them. Age of Ultron - as with pretty much every other MCU movie so far - doesn't offer up much in the way of further explanation, though; when it comes to Infinity War, then, Marvel need to ensure that audiences get a proper, thorough briefing regarding these artefacts.