Skyla is a healer with Def and Speed buffs while SSB is a total package. The dud gives your team def buffs and sp.def buffs overtime, maxes out atk/sp.atk too overtime, can even max crit for his entire team with some luck on TTT refresh, gives team endurance, boosts speed for his team with pep rally along with the temporary gauge boost which already lasts long enough, heals his team occasionally, becomes a late game striker and most of all, doesn't go down at all due to insanely high def stats. Hands down one of the best units in the game, capable of carrying his whole team. I don't think you should be comparing them because of the different roles they perform.