It's obvious why you would use gaara. Gaara (skillbroken) has immobile chase,he gives free shields, and he buffs minato. Those shields are useful so that you cann* use the earth main shield buff while still providing the earth main male combo and attack bonus. Plus gaara does a lot of damage. These would be susceptible to poison, but you'd do enough damage and your mysteries are fast enough that you'd likely kill the other team before the poison had enough time to kill you.

P.S. Oasis's censor system is ridiculous*