This card is treated as a Normal Monster while face-up on the field or in the Graveyard. While this card is a Normal Monster on the field, you can Normal Summon it to have it become an Effect Monster with this effect.● You can discard 1 card, then target 1 Gemini monster in your Graveyard; Special Summon it in Defense Position. You can only use this effect of "Chemical Beast Hydron Hawk" once per turn.
Featherizer allows you to select which Gemini monster you want to discard from your deck, as well as being able to draw a card. This can essentially help you use Hydron Hawk's effect without ending up low cards in your hand. Supervise allows you to special summon a monster the turn you summon Hydron Hawk, which can lead to some plays.
Having 2 gemini monsters allows for some quick plays, especially if you use Supervise on Hydron Hawk. Fusion summon Superalloy Beast Raptinus using your Hydron Hawk, or any monster that you equipped Supervise to, and this will let you get your high level Gemini monster out that already has its effect enabled because of Superalloy on the field. Phoenix Gearfried can let you special summon more monsters, while Darkstorm Dragon can wipe your opponent's back row.