Verified answer

Zenmaine's effect only activates when face-up on the field. If removed from the field for any reason, during the end phase, it's effect is not possible.

Nope your opponent cannot activate Zenmaines effect while hes in the grave.I run Zenmaines on Dueling Network so i basically know its ruling.

Wind Up Rabbit Rulings

1. Due to the fact your monsters result refers back to the activation of a spell or entice, any spell or entice activated prior to the influence summon of the monster will remain intact. 2 The outcome that detaches Xyz materials can also be applied even supposing this card could be destroyed throughout the injury Step in combat or with the aid of a card outcome. The result that activates in the course of the end section objectives 1 card on the subject. The influence of "Wind-Up Zenmaines" that detaches Xyz materials instead when it could be destroyed may also be applied a couple of times during a single flip. Also, even if that effect is activated twice during a single flip, the result that prompts for the period of the end section most effective activates as soon as.[2] So the reply to number 2 is yes, but its outcome that allows for it to spoil anything on the area is simplest applied throughout the end section, and can handiest be activated as soon as. Your opponent cannot connect multiple xyz materials, and then proceed to wreck a card each time you assault finish up zenmaines. He can simplest destroy 1 card per turn even supposing he is attacked three times and discards three xyz materials

You cannot. I play dn also and I use zenmaine in my dark world deck. You cannot.

Simple as what everyone else said. No he can not.