Bam-Boo Sounds like PumpkaBOO and Samurgeist sounds like GoreGEIST
And SAMURgeist sounds like SAMURott.
Not a bad idea, but better names are needed. The gimmick of losing to a ghost type could be replaced by being traded with a ghost type, like Shelmet/Karrablast thing. I'd rate it about 8/10, due to the fact it seems like names have been pinched from Pumpkaboo/Goregiest/Samurott and you are rewarded with evolution for losing.
My AC:CYOA: http://www.gamefaqs.com/boards/997811-animal-crossing-new-leaf/68964849