If you have exactly 3 Normal Monsters in your Graveyard, you can Special Summon this card from your hand by removing from play 2 Normal Monsters from your Graveyard. Once per turn, you can select and Special Summon 1 Level 4 or lower Normal Monster from your Graveyard.
With 3 Balls in the deck, and the ability to special summon from your deck/hand, this can make summoning Red Lotus easier, either by tribute summoning or special summon. Combine this with Order to Charge to take down most monsters your opponent can summon, and send the Shine Balls to the graveyard.
Some variation of Harpie decks uses more normal monsters than others, which can make special summoning Red Lotus easier. Even if you don't have a lot of normal monsters, tribute summoning Red Lotus can still be useful so you can special summon another Harpie, or Sonic Duck back to the field.
Three-Star Demotion Can be used by paying 2000 Life Points. Until the End Phase, reduce the Level of all monsters in your hand by 3. This skill can only be used once per turn.
Gemini monsters are treated as normal monsters, unless they are summoned once they are on the field. You can get 3 in the graveyard by fusion summoning Superalloy Beast Raptinus, and discarding any gemini monster through spell/trap cards or destroyed by battle. Special summoning a gemini monster from the graveyard will also let you normal summon them right away so you can activate their ability.
Banishes from your Graveyard / Banishes from Graveyard for cost
Special Summons itself from your hand / Special Summons from your Graveyard
My experience with this guy is trough geminis, in which I can assure he have helped me on several occasions.
As they do take up several of your Normal summons, you ordinary don't want to fill your entire deck with 5+ gemini monsters, unless you got another way to get them out or support for them. So chances are you'll have the cards to combo with this at any time. A mid-game [Magical Reflect Slime]-resurrection chain with this guy is one of many lethal combos out there.