Battlefield action: Then I throw candy apples at the ghost guard at relativistic velocity.
Mass of an Apple - 100 grams
Assumed Relativistic Speed - 0.99c
Result - 5.473e16 joules or 13.08 Mt
City level by VSBattle Wiki standards and Low City level by OBD standards
This is the 2nd most numerically destructive attack, the 20 Mt nuke mentioned earlier beating this out