I had this randomly pop in my head. With how SE doing all the jobs in FFXIV(Mixing ability's up from FFXI classes to put it short then make ur own class) BST and SMN could be 1 class if/when it comes out.
Mostly it goes like this. You pick the bst/smn class, and you go out killing to get dna from the monsters you fight. Once you got the dna you can summon that monster to ur side and help you fight.
Not sure how it would work out. I just got bored playing tower defense games, and that came up. lol, but hey its a thought on how they could be implanted.