Mystcraft is actually broken by Forge 665, though. This mod just needs to be redone with reobfuscate_srg. I know it works because I deobfuscated/reobfuscated it myself yesterday and have it running on 1.5.2 just fine.
Updated to Beta 0.1.13 for Minecraft 1.5.1 and 1.5.2. Fixed the bug where the Force Infuser did not work in dimensions other than the overworld. Also fixed the bug where Spoils Bags dropped without initializing and therefore vanished. DartCraft should now run on any version of Minecraft that is not significantly different from the one it was designed for. Added recoloring recipes for Force Bricks using vanilla dyes. Force Armor is now directly upgradable instead of socketable. Added various upgrades to the Force Armor, including the new Bane and Bleed upgrades. Added the Force upgrade to the Item Card and two new cheat commands.
Thank you to everyone who pointed out the dimension glitch. The Spoils Bag glitch was already fixed by the time I checked this thread, but then you guys gave me a new glitch to fix. The reobfuscation method has been changed in favor of a less version-dependent one, but I only spent an hour or so testing DartCraft in 1.5.2 so complete stability is not guaranteed. Have fun!
I'll need a full verbose error log (pastebin please) for the NEI error as I have tested DartCraft without CodeChickenCore and NEI and was unable to get it to crash. Something I've noticed however, is that my custom tooltips inside the Force Infuser and Force Engine do not appear if NEI is not installed. Until further notice it is my official position that CodeChickenCore and NEI are required to play DartCraft, although that may not actually be the case.
As for the Force Gems - absolutely they are based off of the Legend of Zelda. They were taken verbatim from the Legend of Zelda, as were several other items from DartCraft. When I went to make a mod I decided to cram in as many Legend of Zelda references as I could. Can you find them all?
Until further notice it is my official position that CodeChickenCore and NEI are required to play DartCraft, although that may not actually be the case.
I'm fairly certain your mod is dependent upon NEI, because when I deobfuscated/reobfuscated the previous release to get it working on 1.5.2, I had to include two files from NEI, namely IConfigureNEI.class and IStackPositioner.class. I reobfuscated with those two classes from NEI present, then deleted them afterward, and your mod's .12 release worked fine (with NEI installed).
MINOR BUG: When I have the Wing Effect going on, I seem to have a VERY hard time going through doorways and going up steps. I especially notice this when trying to going up the front steps of my house, which are sitting on grass blocks. I hit the bottom of the stairs and just stop.
I think there's a world gen problem here if Biomes O'Plenty is installed. I was annoyed that I couldn't find a single Power Ore after spending quite a bit of time, so I checked MCEdit if it could find any blocks with the ID 1900 (which is the one I got for it) and... none. Quite a few explored chunks, and absolutely no mention of that ID in MCEdits's analyze funciton. No instances of that ore seemed to show up on this test instance with only BoP and DartCraft as well.