>>5515327IDW's been trying to explain how sparks work in their continuity, but it's been a mess since they only talk about it every now and then. So far we have:
-Sparks that are found, or dug out of hot spots
-Sparks that come out of the Matrix (this being IDW, this is treated as the worst thing ever)
-That not all sparks are cable of working with any body. Some are only suitable on bodies that can fly, and may be limited in the size of the body
-Point One Percenter, special sparks that are more powerful than normal sparks, and seem to have their own categories that haven't been discussed in detail yet.
-Outlier, a transformer gifted with special powers that stem from their spark (Trailbreakers shields, Windchargers magnetic powers, Skywarps teleportation, etc...)
Body switching is a tricky subject. It's not known why more characters don't go for it. We know new bodies have been built for a few characters in IDW, but it's not been discussed in detail {notably, the characters who switched were Optimus temporarily), and Megatron, both Point One Percenters, but Starscream is normal and also got new bodies}, other characters just seem to alter the bodies they already have. That being said, bodies seem to still be something they turned into originally, and not entirely different. When one character switched to a body he wasn't capable of using, their spark burned out after a while.
