In Pokemon X and Y, you can use both Hatch O-Power and Flame Body to reduce the amount of steps it takes for an egg to hatch. If I use Hatch O-Power and Flame Body, how many steps will be removed from an egg that requires 10000 steps ( I used 10000 as an easy way to compare to other amounts)?
Hatch O-Power 3 and Flame Body will each halve the time taken to hatch the egg. With both, the egg will take a quarter of that time.
An egg which would take 10000 steps would take 2500.
Although Hatching Power can stack with the effects of either ability; the effect will not stack up if multiple Pokémon with Flame Body and Magma Armor are in the party.