Reg's incinerator needs to do more damage. It currently does about 600 damage, which is not enough to kill a single clockwork monster in ruins. That's not enough to justify his use underground.

As a bulk mob clearing mechanic in ruins - the ultimate destination for Riko + Reg - consistent with its purpose of saving Riko in the show, it would make more sense if it dealt enough damage to save Riko then left himself unable to attack for a period of time.

800 damage to anything in the line of fire is enough to kill clockworks
1300 damage is enough to kill spider queen.
Consider adding a longer sleep period to compensate for damage increase and make players think carefully before using (e.g. leave Riko helpless).