Didn't See this one done, Since Avatar Is an american animated show this shouldn't be banned.
Fight takes place In the Sahara Desert both have a Gallon of water.
No Prep, Both are aware of each other's power. Katara at her Prime, Mera at her current power level.
STRICTLY AN ELEMENTAL FIGHT, NO H2H!!
Round 1: Morals Off
Round 2: Morals On (Which means no blood bending!)