I'm very new to the game, and am wondering what I should do. I've saved up 25 skill shards, enough to fully upgrade my Samurai Eddie. Is that a smart choice or would it be better to upgrade a couple of my support characters? For example, I have a Soulless Demon (Sentinel) and Child of the Damned (Magus) that I use a lot right now. I'm leaning toward upgrading Eddie, but it seems like skill shards are hard to come by so I don't want to waste them.