"Elemental Hero Neos" + 1 Warrior-Type monster
This monster cannot be Special Summoned except by Fusion Summon. This card gains half the ATK of the Fusion Material Monsters, except "Elemental Hero Neos". This monster can attack twice during the same Battle Phase. When this card battles, any Battle Damage to your opponent becomes 0.
In the case of king of the swamp and a warrior(lets say goyou), does neos knight gain attack base on BOTH king of the swamp and goyou which is 1650, or 1400 only. Since after fused, king of swamp is no longer labelled as Ehero neos.