Not really a delve, but the adventure taken from Monster Vault. I wanted to try something really weird, and ended up with a shardmind shaper psion. Shardminds are an annoying race in that I can't really think of a working character concept outside of, "you're in the natural world, trying to kill aberrants." Great if you're running a campaign frought with aberrant baddies, but...not so good in any other circumstance. Also, they're very alien looking, falling outside what the arbitrary acceptable non-human traits of other races (glowing eyes, horns, tails, and/or fur).
Since it was a delve I wasn't surprised that the party and townsfolk never questioned my existence or purpose. I'd elected to go with the shaper class feature, because I enjoyed forging astral constructs in 3rd Edition, and while I knew I couldn't do it so easily in 4th Edition wanted to see if it was still enjoyable creating more bizarre, temporary things as even at level 4, none of the at-will Conjurations were humanoid in shape. Instead, I could create shards of force, static motes, and...whatever the hell a psychic anomaly is.
The first encounter in the adventure consists of a cliched viking boat dropping out of the sky and unloading more undead that what could fit into it. Thankfully, a lot are minions, but since our DM wouldn't indicate which I decided to reserve power points and throw out a static mote. Initially, it only slows things that start their turns next to it, and on the following round explodes into a Close burst 3 attack. Anything next to it has to basically double move (or teleport) to get far enough away to avoid it. This, combined with the fact that it targets creatures, made it somewhat annoying to use.
The Most Useful Power award went to psychic anomaly. This thing is awesome, and aside from the occasional force shard I used it exclusively throughout the session. You drop it on your turn, and anything that starts next to it gets hammered by an attack. The best part is, that if you burn a power point then allies can flank with it, but if you spend two it also dazes them. This, coupled with our skirmishing warlord's knock-back attacks, helped us keep the heat off of our gnome paladin, who unfortunately still got dropped about five or so times throughout the session.
After we dispatched the undead, we talked with the boat, which allowed anyone on that affirmed having the ice scepter, whether or not they actually did. Figuring we'd need it later, we bothered to dig around and found someone that happened to have just the scepter we were looking for. After that we got on the boat, and were subjected to a lengthy and annoying skill challenge. There weren't a lot of skills that we were allowed to use, and thankfully the DM was kind enough to ignore the fact that we'd accrued a good deal more than three failures by its conclusion (though we were a healing surge worse for wear).
The entrance to the dungeon is indicated by a massive pile of skulls encased in ice. We didn't spend time checking it out after the DM mentioned as an aside that it had some form of attack. On the other hand, the first room was warm and inviting, with an old man claiming to be the Winter King and swearing that he'd drop the curse if we handed over the ice scepter. Beth's gnome, being fey and all, outright refuses any kind of "free gift". Good advice. None of us trusted this guy, especially since the NPC that nabbed the scepter in the first place described an ice-filled cavern with people frozen inside.
So combat starts, everything's revealed to be an illusion, and we get our asses handed to us a second time. Now, the DM claimed to have yanked a dire wolf from the mix, but the fact that we had to go through Action Points, healing potions, two inspiring words, one lay on hands, and multiple daily powers tells me that either this encounter is not balanced at all, or that we were doing something very wrong. On one hand, Beth and I were playing classes that we weren't familiar with, but on the other hand we were pretty damned optimized.
Many rounds and healing surges later, we decided to make camp for the night in a storeroom, and were awoken when someone heard a patrol outside. The patrol consisted of a bunch of tiefling minions, some guards, and a gnome. Things went easier because we propped the gnome in front of the door and just blasted them from the safety of the room while our halfling assassin zipped about outside murdering stragglers. The gnome got away, and we came out having used our dailies only under the pretense that A) this was a one-shot, and B) we were calling it for the night.
Did I like the adventure? Well, when I read it, it looked really cool. Not sure if I'd fault the DM, luck, or the encounter composition, but something was definitely awry.
Did I like the psion? Yes. I think I'd swap out static mote for something a little more direct. Perhaps something with forced movement so that I could use an action point to drop a psychic anomaly next to more critters (or to just have something that doesn't require monsters to start next to it). I'd certainly try it again, but probably not as a shardmind unless its something more central to the plot.