Question: are z moves special or physical?
Answer: Damaging Z-Moves derive their category (physical or special) and power from the original move. For example, a Gigavolt Havoc based on Nuzzle (with a power of 20) will have a power of 100 and be a physical move, while one based on Thunderbolt (with a power of 90) will have a power of 175 and be a special move.