It started with laser-guided missiles, then laser levels, then laser guided power tools. Let's take lasers back to the iron age.
Small laser modules that can run on 12 volts or less are readily available and cheap. Using the line-type laser will make this project work. It will project a line onto the log you are splitting in the raised position through mid-stroke into contact, making it easier to hit that where you want.
Powered by a 12 volt lipo battery pack (3s), it can sustain a line for the whole day.
Shock absorbtion will be a key for improving the longevity. Using a mount that provides dampened isolation of the laser unit will substantially extend the usable life of this device.
Future improvements may include a split-cam, stroke counter (for cross-fit), and a burning laser to both split the log and start your fire at the same time.