Also, Sacchi, if you're leading with your Tyrannos for now, you should have the entire rest of your team be red. At your point pretty much anything red should probably do (you should especially try to pick up a goblin or two, after they're Samurai Goblins they can turn hearts into red orbs)
Also try to grab an ogre of any color (at any stage) and keep it low level, your can use it as your leader with an autoheal friend (any stage of Siren, Alralune, Angel, or Amaterasu) to try Wednesday and Friday dungeons on the harder difficulty - dublits of any color (dubmythlits especially but those only come in dark) make pretty decent early subs for a cost of only 1.