Oh, by the way, how does special attack creation work? I looked at bite, and I didn’t see how it worked at all. Could you try to explain this (unless it is in world creation notes)?
Aside from the conditions for use, most of which should be fairly self-explanatory (though I suppose I do need to add the mouseover text), all of the details of a technique are determined in the keyframe editor (under "animation and behaviors").
A technique is essentially a series of one-frame functions. You can navigate the keyframes by clicking on the small bar at the bottom of the left column; vertical lines represent frames that have data set to them.
Let's dissect the spider's Bite technique.
The bite is a close-range (16 pixel range) attack that creates a hitbox that applies a poison effect on contact. An AI spider will check for available targets (nearby enemies) at random, no more than 120 frames since the last check. If it finds a target, it will spend 90 frames attempting to get in range (16 frames away). If it fails to get in range, the technique is cancelled. When in range, the technique will activate. Basically this means the spider will occasionally rush forward to bite a target. (A player controlled spider will skip this step; the technique will be available when 16 frames away from an enemy as long as it is not on cooldown).
The technique itself has 2 keyframes (actually 3, but the first one is just a log event I used for testing). On frame 10 it temporarily sets speed and turning to 0, basically cancelling all movement. On frame 15 it creates a hitbox 16 pixels in front of the spider. (I actually had the positioning off before; it is supposed to be {16,0} not {0,-16}, which places the hitbox to the left of the spider instead. I fixed it, but if you copied the code for your Phantom Spider you will need to change it.) On contact, the hitbox triggers the spider's "venom" function.
Since there's currently no support for real status effects, the venom function works by creating a "poison" sprite (a hidden sprite packaged with the spider) and setting the poison's "target" variable to _other (i.e. the sprite that the hitbox made contact with). When updating, the poison object positions itself on the target and drains the target's HP.
Techniques can be used for many things, although as previously mentioned vertical targeting is still kind of wonky, especially in sidescrolling mode.