I'd say an eight. I think the two would get along so much that they'll make it an interesting fight for sure.

It would end fast, since Charizard would probably win. Also, a nurse's pokemon is basically for healing right? So it might not have good attacks.

thing is thow charizard is fire Meganium is grass fire is strong ugensed grass.

Though it might end fast because fire does have a huge advantage over grass,and I most likely would enjoy it because it does have Nanako-chan/Casey in it..but this one i'm not exactly feeling it for :p