One of you pick Lucas, the other pick Zelda.
Zelda spams Din's Fire, Lucas gets protected by the explosion of Din's and uses PKT2 to kill people. if someone decides to try to shield it, throw a Din's in that persons direction.
It requires a decent Zelda, but shes basically playing protection for Lucas, While Lucas' PKT2 does massive damage.
or...... Zelda stands on edge of map and spams Din's, Lucas stands slightly in front of her and spams PK Fire. If someone tries to approach via air, just have Lucas Nair and Zelda Din's the person at the same time.