[Timstone]

Well this conversation about energy and unknown lifeforms is very interseting, but since we've never encountered such a race before, let alone ANY alien, we are just guessing in the dark. But I have one addition to make.

Quote from SJ:
Its like waves on water... if you have a wave from a boat coming and you throw pebbles into the water, the waves pass though each other, and both waves continue as if the other weren't there.
Up to the point where you start making splashes, of course.

NO, NO, NO!! The waves don't just pass through eachother, they interact with eachother. The wave that goes from left to right gives A PART of it's kinetic energy over to the wave from right to left and vice versa. This energy creates another wave on the "back" of the other wave. They just seem to be passing through each other. EVERYTHING that has only the tiniest bit of energy in it interacts with it's environment. Except when the particles involved have such a high velocity or such a high mass (density) or a neutral charge (chemicaly inert or simply no electrons of protons (or their antimatter counterparts)).

Well we're dwelling of the subject of the matter (oh no, I said matter, hehe...). So what will be the best solution for our problem? I still think the Walkers must have the -999% to hit bonus on their armor and the Mindriders something else, but I don't know what.

Oh, the Vorlons, the Walkers, the Triad and the Mindriders are all energy beings. The Triad were energy beings from the beginning. The other three "just" evolved into beings of energy.