Who is the defending Pokemon ?

[Sceptilious]

Is the Pokemon you are attacking the defending Pokemon? For example if you attack the bench with an attack like Charizard G Supreme Victors - [1R] Flame Jet - Flip a coin. If heads, this attack does 40 damage to 1 of your opponent's Pokemon. (Don't apply Weakness and Resistance for Benched Pokemon.) If you chose a benched Pokemon as the target is it the defending Pokemon?
If it is, does Cherrim Stormfront's Sunny Day - Each of your G Pokemon's and R Pokemon's attacks does 10 more damage to the Defending Pokemon (before applying Weakness and Resistance). (Poke-BODY) add 10 damage to the attack?

Thanks in advance !

 

[bulbasnore]

The 'defending pokemon' is your opponent's active, never anything on the bench.

So Sunny Day will not increase damage for bench attacks.