Here's a list of fusion ability cards you can use
Depth Flare: Increase your Pyrus bakugan by 100 Gs.
Distraction Buster: Negates your opponent's Ability card.
Destruction Impact: Allows your Dual Hydranoid to nullify your opponent's Gate Card, and increase its own power level by 100 Gs.
D-Strike Extreme: Increases your Delta Dragonoid's power level by 200 Gs.
Exceed: Increase your Ultimate Dragonoid by 200 Gs.
Final Demolition: Increase your Ultimate Hydranoid by 100 Gs.