An iron axe, 25 blocks of range, a 4 block radius, an 8 second cooldown. You aim, lightning falls.
The Thor is the opening kit by definition: it chips a whole group before contact is even made. In exchange, the bolt is loud and bright — after the first strike, the entire arena knows where you are and what you are playing.
Eight seconds is a long time. A Thor who wastes his lightning is an ordinary PvP kit for eight seconds.