OCG Rulings

• Detaching 1 Xyz Material is a cost.^[1]

• This effect targets 1 face-up monster the opponent controls.^[1]

• Inflicting damage to the opponent and increasing this card's ATK are considered to happen simultaneously.^[1]

• The ATK increase lasts as long as this card remains face-up on the field.^[1]

• If "Number 33: Chronomaly Machu Mech" effect targets a "Blue-Eyes White Dragon" that was Special Summoned by the effect of "Hieratic Dragon of Tefnuit" and whose ATK and DEF became 0, the opponent takes 3000 points of damage and "Number 33: Chronomaly Machu Mech" increases its ATK by 3000.^[2]

• If "Prime Material Dragon" is face-up, the effect can be activated. However, at the time of the resolution of the effect, the effect of "Prime Material Dragon" will switch the damage to recover Life Points instead, so the effect will only recover the opponent's Life Points by the difference between the ATK and the original ATK of the selected monster. Furthermore, since the opponent doesn't take any damage as a result of the effect of "Prime Material Dragon", the effect that increases the ATK of "Number 33: Chronomaly Machu Mech" is not applied.^[3]

• If the effect of "Number 33: Chronomaly Machu Mech" is activated targeting a monster whose original ATK has been modified by the effect of "Unstable Evolution", the damage inflicted is equal to the difference between the modified original ATK and its current ATK, and "Number 33: Chronomaly Machu Mech" gains ATK equal to that amount. Furthermore, if the monster's ATK is only being modified by the effect of "Unstable Evolution", the difference between the monster's current and original ATK is treated as 0 and it cannot be targeted to activate the effect of this card.^[4]

References

1. ↑ ^{1.0 1.1 1.2 1.3} Konami OCG FAQ: Xyz Monster > Number 33: Chronomaly Machu Mech
2. ↑ Konami OCG FAQ: At the time the effect of "Number 33: Chronomaly Machu Mech" is activated, if this effect targets a "Blue-Eyes White Dragon" that was Special Summoned by the effect of "Hieratic Dragon of Tefnuit" and whose ATK and DEF became 0, does the opponent take 3000 points of damage?
3. ↑ Konami OCG FAQ: If "Prime Material Dragon" is face-up, can the effect of "Number 33: Chronomaly Machu Mech" that inflicts damage and then gains ATK equal to the damage inflicted be activated?
4. ↑ Konami OCG FAQ: If the effect of "Number 33: Chronomaly Machu Mech" is activated targeting a monster whose original ATK has been modified by the effect of "Unstable Evolution", what does the ATK of "Number 33: Chronomaly Machu Mech" become?