|Hadesu no Haato
Hades's Heart (ハデスのハートHadesu no haato) is the Underworld god's heart. It is the boss of Chapter 23, Lord of the Underworld in Kid Icarus: Uprising. It has two legs to move, uses its arteries and veins for melee attacks, and what seems like an eye in the center of it's body. However, defeating it doesn't kill Hades, but weakens him by a significant amount, possibly a major contribution to Hades final defeat in The War's End.
In Kid Icarus: Uprising
Hades's Heart is fought in Hades's chest, within a large maze. When first encountered, it seems quite easy to follow the heart around and attack it. However, after a while or after taking enough damage, it will create a copy of itself, which can be told apart from the real one by its yellow aura. Eventually, the copy will explode, sending vertical and horizontal columns of flame, though the flames do not pass through walls. The areas that will be covered by the explosion glow briefly, which can assist players in staying out of the blast range. The heart may also drop mines, but these have a low blast radius and are simple to dodge. After the real heart is dealt a certain amount of damage, it will gain a red aura, speed up for ten seconds and try to run into Pit; in addition to all this, it is invincible while its aura is active. It is possible to dodge these rams, but the Heart's copies following Pit around make this task harder. Long-ranged weapons with strong homing abilities (like Bows) are useful since it's possible to shoot over the walls and hit the organ. Clubs are also effective in this battle since they all (except the Atlas Club) have charged shots that can travel through the walls. The Slip Shot Power is also useful.
At least this is as close to a "heart" as someone like Hades could have. Clearly not made to pump blood, Hades's Heart moves and acts like it has a mind of its own, wildly running around its enemies and setting traps as it goes.
The AR Card for Hades's Heart
Artwork of Hades's Heart and the maze it is fought in
Pit fighting Hades's Heart