Inferno Overdrive inflicts damage. Its power and whether it is a special or physical move depends on the move it is based on.
If Breakneck Blitz is used during harsh sunlight with Weather Ball as its base move, it will turn into Inferno Overdrive. This does not occur if Weather Ball is turned into a Z-Move via another move like Sleep Talk.
Turtonator strikes a series of synchronized poses with its Trainer to build Z-Power. It then gathers a large ball of fire in front of its mouth and launches it towards the target.