I have a Rypherior with the ability Lightningrod, and a Volcarona that knows Rage Powder. If I have both of those Pokemon out in a double battle, what will happen if Volcarona uses Rage Powder and my opponent uses an electric type attack?
If another Pokémon becomes the center of attention, Electric-type moves will be directed to it instead of the Pokémon with Lightningrod.
To simplify it, all electric moves will be drawn to the Pokemon who uses Rage Powder. So no, Lightningrod will not work.
Source
It will draw the moves toward the Pokemon that used Rage Powder.
Volcarona will take the hit >If a Pokemon with the ability Lightningrod and a Pokemon using Rage Powder are out at the same time, and a Pokemon uses an Electric attack targeted at the Rage Powder user's team, Rage Powder will take precedence and absorb the attack.
Smogon
If a Pokemon with the ability Lightningrod and a Pokemon using Rage Powder are out at the same time, and a Pokemon uses an Electric attack targeted at the Rage Powder user's team, Rage Powder will take precedence and absorb the attack. If a Pokemon with the ability Storm Drain and a Pokemon using Rage Powder are out at the same time, and a Pokemon uses a Water attack targeted at the Rage Powder user's team, Rage Powder will take precedence and absorb the attack. Rage Powder will take precedence and redirect attacks before Magic Coat or the ability Magic Bounce take effect.
Rage Powder will take priority and absorb the hit instead of Lightningrod