Official Errata

Followed should say Interrupt instead of Response. Meaning, Followed will trigger before a side scheme is discarded.

Q: If Followed is attached to Legions of Hydra, will I be able to deal 4 damage to Madame Hydra after defeating Legions of Hydra?

A: No. Followed is triggered before Legions of Hydra is discarded. So Madame Hydra will still be immune to damage while Followed is resolving. -(Developer Ruling)

• Damage of 4 by doing what Justice aspect does better: defeating schemes
• Can be triggered on Alter-Ego, which is an apreciated rarity.
• If cleared while the intended minion is down, it can still hit the villain for some progress
• Requires a side scheme to work with. Player side schemes are here to help if villain deck dont cooperate.

I think its not a bad card, and is on par for its cost, can be stored on the field for later; yet its requisite can be too restrictive in some situations. Would add one or up to two of these (except if playing with Cable (Hero), whom deck speaks the language of side schemes)