Koumori Dragon + Minomushi Warrior → Stone D.

Koumori Dragon + Stone Ghost → Stone D.

Koumori Dragon + Kaminari Attack → Twin-headed Thunder Dragon

Koumori Dragon + Tripwire Beast → Thunder Dragon

Koumori Dragon + Bolt Escargot → Thunder Dragon

Koumori Dragon + Bolt Penguin → Thunder Dragon

Koumori Dragon + The Immortal of Thunder → Thunder Dragon

Koumori Dragon + Electric Snake → Thunder Dragon

Koumori Dragon + Armed Ninja → Sword Arm of Dragon

Koumori Dragon + Magical Ghost → Dragon Zombie

Koumori Dragon + Sea Kamen → Spike Seadra

Koumori Dragon + Ameba → Spike Seadra