To avoid a lot of damage I can honestly tell you how I kept first for so long on my server pre-merge. Check everyone, if they lack hit rate it might be a slight waste of stones but.. Yachiru dodge vanguard + Tegen Zanpakuto. I had max Dodge (well 130%) and most of the time no one could get fury to do any damage. It's situational as it requires players to be lower hit rate for pretty much 100% success and only really works at lower levels but should give you a big enough lead to help you down the road. Also, could make yourself a OP Sado with as much block you can muster on him with Strength / Wisdom / Block refines. Add Revive enchant to his weapon if defense is high enough (most players you fight should do max 5 damage) using the revive to heal the damage you take from zanpakuto.