Tribute this card during your Standby Phase after using "Mass Hypnosis". It's an odd combo but it can be effective. Not only will "Jigen Bakudan" do damage but it will also get rid of most, if not all of your opponent's monsters setting up for a possible OTK.
A rather hard OTK is to summon "Satellite Cannon" and then, after 16 turns without attacking, you can flip "Jigen Bakudan" to destroy the "Satellite Cannon" and inflict your opponent exactly 8000 points of damage. With "Limit Removal" you can already perform this OTK in 8 turns.