First round: ramdom encounter, no weapons or shen gong wu, aang can only use the air, no avatar state
Second Round: A week of prep, XD have their sheng gon wu (rai has the sword of the strom, kimiko has the star hanabi, clay the third arm sash and omi his ord of tornami) team avatar has their weapons, zuko's swords, aang's staff with all four elements, during the fullmoon
Thrid round: A week of prep, the XD have their elemental shen gong wu and their wudai weapons, aang and zuko have the sozin's comet power and katara has the fullmoon's power, and to make thing more intresting zuko can generate lightining and blue flames and katara in wiling to use blodbending and aang has the avatar state.
fight takes pace here
each team from the end of their series victory by k.o., in character