I do not plan. But it doesn't hurt to visualize the odd individual mechanical outcome. In this case, I thought, well, since they muffed the Skill Challenge and unleashed the crystal creche thingamabob, then Our Land is not just currently compromised by an invasive mystical-crystal birth event, it's basically lost out to it. So if either Urri and Irru gets through the Door, then they'll merge into a horrible anti-purpose un-Our-Land cosmically-retrogressive aberrant threat of their own, as Our Land comes apart all 'round and our heroes will have to cope with a new mini-setting. Maybe even get transmuted into shardminds, for two of them; that oughta be fun.
That was before the Arcane Mutterings, recently acquired in Eneku's level-up. It lets him use Arcana to substitute for other social skills, once per encounter. Pretty cool, right? And in play, yes it was, as Gordon was born to deliver the appropriate dialogue, such that the rest of us would go what the fuck? ... oh wait, that sort of does make sense. It also did a dandy job of getting the twin-demi-deities through the door in concert with reconciling them to the crystal influence. As in, if either one or the other had happened first, then whammo, see above.
I'm good with whatever happens. But you can bet I had my bookmark already set to the displacer beast, which is what I planned to re-skin for the above-mentioned horrible et cetera, with a nasty addition or two from the DMG2 options as well. Suddenly shifting to ... wait - it worked? left me without a handy visualization. Playable, yes, but I had to scramble for a moment, you can probably see it on my face, as I was forced to admit that instead of New Weird Crisis, it was time to play Mysterious Serene Denouement.
Don't let that distract you from the details. I was pleased to see their reactions to my characterizations of Urri and Irru swing back and forth between "these two are nuts!" and "maybe they aren't so bad." The fight against the crystal cobra brought in some great moments, although it also showed me it's time to start using solo foes of their level or just above, rather than single foes well above their level. Perhaps counter-intuitively, the latter are less difficult if you can get past their basic trick. Eneku displayed Karnak-worthy martial strikes and Runt pulled off one of those roll-to-hit-again barbarian combos, neither of which would have brought down the cobra alone.
And if I'm not mistaken, all the players are now feeling well into their characters' skins, er, integuments, running with the weird and providing energy to make it go rather than relying on me. Runt is turning out to be a very complicated fellow, as you'll see.
What's next? The plan was to shift up to 11th level to see what Paragon play is like, but upon reviewing the process, I'm thinking a one-level stop-off at 7th is a good idea. That's a key point for hybrid-built characters, where you start being able to choose things freely instead of making sure you have one of each class for each type of thing. It also, as I see it, is just about the point where you look ahead to Paragon tier to see what might be most interesting or the best fit.