I name my decks whatever the heck I want to name them, based on what I feel like. However, if people ask what I am playing, I won't give the custom name for it, usually - I'll give the name that most people are used to. For example, I call Zekeels+Terrakion "Zekkion", but that's not what I'm going to tell people; I'll be straight-forward about it.
Also when something is implied, like Darkrai in Hydreigon, I won't mention it. If I say I am playing Hydreigon, it is implied I am using the Dark Trance version, and with Darkrai EX. But if I have to explain the name for my deck in more than 30 seconds, it's more worth it to just say the name that people are more familiar with.
Then again, it is possible to be straightforward and confusing. When I tell people I run Victini Donk (which I do), they are met with a blank stare. (Hint, it's the Psychic Victini.)
Also when something is implied, like Darkrai in Hydreigon, I won't mention it. If I say I am playing Hydreigon, it is implied I am using the Dark Trance version, and with Darkrai EX. But if I have to explain the name for my deck in more than 30 seconds, it's more worth it to just say the name that people are more familiar with.
Then again, it is possible to be straightforward and confusing. When I tell people I run Victini Donk (which I do), they are met with a blank stare. (Hint, it's the Psychic Victini.)