Etched Champion's ability means he has protection from all of the colors, so white blue black red and green. Colorless isn't a color, so he Ratchet Bomb would have no problem destroying him.
Ratchet Bomb does not target in the first instance but yes, it would destroy the Champion regardless of whether it had Metalcraft or not because Ratchet Bomb is colourless
Player B has a etched champion
Can player A use the ratchet bomb to destroy/remove the etched champion, or does the champion have protection from colorless as well?
Thanks
Damage
Enchanted/Equiped
Blocked
Targeted