Toad, Tongue Lashing, Uncanny X-Men, #59, Sidekick attacks

Toad - Tongue Lashing
Does the burst effect, causing 2 damage to attacking characters, apply to all characters that attack, or just the non-Sidekick characters referred to earlier on the card. If Sidekick characters attack, would they also take 2 damage?
While Toad is active, each opposing non-Sidekick character must attack (if legal).
* Opposing characters take 2 damage when they attack.
Does the burst effect, causing 2 damage to attacking characters, apply to all characters that attack, or just the non-Sidekick characters referred to earlier on the card. If Sidekick characters attack, would they also take 2 damage?