Summoning multiple monsters from your hand quickly can result in a card disadvantage. This will make it more difficult to comeback if your opponent can counter them due to lack of cards that can help with more draws.
Cost Down can be used to reduce the level of the monster cards in your hand.
Water Hazard can be used to special summon Hammer Shark so it doesn't use up a normal summon.
Hydro Pressure Cannon will be equippable to Hammer Shark if it's able to activate the ability at least once.
In case people want to know the bosses were:
1 - Black Ray Lancer
2 - Shark Drake
3 - Abyss Splash
4 - Silent Honor Ark
Out of his 4 different bosses monster.
I have to admit Shark Drake was my favorite one.
It was probably the most dominate boss monster for the majority of the series.
It was also the hardest to summon which always made duels awesome to watch!
3 level 4 monsters to summon? lo
Haha, I know what you're saying! Hammer Shark + Needle Sunfish = Black Ray Lancer would be brutal. A good XYZ with the bonus of lowering -500 ATK, thanks to the effect of Sunfish? Count me in!
Shark Drake was my favorite too. Dominating, strong AND badass.