I made some updates as suggested.

Indeed, if you're any good at farming, it should be possible to have your RoA before the 20 minute mark. If it doesn't seem like you can get it before that, you should probably think about builing it in a BV or something like that. If you build it any later, it really isn't worth it's money. it's still good, but you would have been better off building something else. But that's an whole other discussion^^

Great build btw, but I think your masteries are wrong. Well, the three points in Perseverence are, the rest is fine. let's do some small math: 4% means you get 4 extra manaregen/5 if you already have 100, which should be more then adequate allready. But you only have 12.5 base at level 18, so this ability is not even adding .5 per 5, so that's just a waste of three points. There is never a good reason to pick perseverence over Good Hands. Because sometimes those extra 2 or 3 seconds make the difference.

Overall a very good guide, just those two masteries should be reversed: three points in Good Hands and one in Perseverce (Because you don't use gohst or teleport. If you use one of those, drop the point in perseverence and take the associated mastery. =)

Boots and WotA is actually only 3k gold. Remember Morgana is a farmer. On average, I can build a RoA within 20 minutes of playing and definitely have it completely filled up within 35 minutes. A decent game takes at least 40 minutes.

If you really insist on rushing it there is no huge harm in building it before WotA.

I really think if you're going to get RoA, you can't build 2 big items before it.

Well the support is kinda embodied in the way of playing, not really in items per se. With all Morgana's inherent control and a touch of Will of the Ancients and Rylai's Crystal Scepter she supports a decent amount. It's reflected in the Kills/Deaths/Assists ratio quite well actually, which points in the direction of a nuke/support.

As for Soul Shroud I think the item is actually very promising begin- and midgame, though I'd probably sell it and replace it with Rylai's Crystal Scepter near the end. For example, I could build it before finishing my Will of the Ancients and then dump it when the mana problems are history.

Awesome guide indeed, though there's a small coding error in your Ionian Boots of Lucidity description. Might want to fix that. Overall, nice guide! Hope others see it too. :)

Also, what do you think of getting Soul Shroud on Morgana? I know it's not the best item out there, but you say you build her 50:50 in supporting and nuking, while the majority of your items are geared towards the latter. Plus, with Soul Shroud you're not that squishy. I know you've already got Spell vamp and Rod of Ages, but this item might help your mana issues, right?