Name a specific Pokemon, and ask someone else to name a Pokemon that starts with the last letter

Correct

And @PokeMom244 just said we can use forms for our answer, but that leads me to a question

Could I use "Mega" for M and "G-Max" for G?

Yes

I don't think @PokeMom244 is too lenient

I think that she doesn't want to be too controlling by placing a whole lot of rules

I think she's trying to let us have freedom

But I could be wrong