Board Thread:Questions and Answers/@comment-1457172-20150614180624/@comment-1457172-20150621154658

Alright, I think I managed to answer this myself. When a Keshin is summoned, that player becomes their Keshin, for the most part. Keshin battles and Shoot battles involving Keshin on either side are dependent only on the elements of the Keshin involved, not those who summoned them. Not 100% on whether this is the case when talking about a normal command battle where only one person has a keshin out, though.

Similarly, it doesn't matter what the element is of a person you give a Keshin to as the Keshin doesn't recieve a same element boost in that regard. This said, Keshin do gain boost if they share an element with their hissatsu. The real benefit of having Keshin of the same element of the player their on really comes from Keshin Armed, as elemental skill boosts now directly affect the player's hissatsu (coupling that with a same element bonus and the power of Armed- possibly Mixi-Max, too, grants a gigantic boost).

So I just gave Tsurugi Taiyo Shin Apollo and let the wood player borrow Fire Tornado DD to take advantage of Taiyou Shin's Fire Element boost when armed.