What to do with this? There aren’t too many worthwhile X-spells in these colors. Some card draw, sure, and hydras, but putting 21 X-spells into the cube seems like an awful idea. So, I’m going to just put fun cards here. And UG does have some of the best of those.
Since I don’t have any real theme here, I’ll go with morph, since I like that theme very much after playing plenty of Khans draft.
Kruphix’s Two-Colored Cards
Unexpected Results is best of the best, when it comes to fun.
Urban Evolution isn’t fun in the same manner, but it is good.
Species Gorger is one of those cards with downside, you can “cheat” into being good.
Nimbus Swimmer would be nice, but its also quite boring.
Plasm Capture could actually be a card that has good synergy with Kruphix. At least a little bit.
If mana burn rule wasn’t lifted (and its a good thing it was), Pygmy Hippo would be fun.
Sharless Agent would be great, but well above budget restrictions.
Enshrined Memories seems legit.