Why does this sentence need "yourself"?
Great question! The sentence here does not need to include "yourself", however, adding it emphasizes his singularity and implies that the Pokemon partner is possessive, and it is only for him. It is commonly used in American English. This grammar structure can be used for other pronouns as well. Ex: She just brought herself a new puppy. Ex: After I walked downstairs, I found myself forgetting what I was looking for.