A Link to the Past
Bombos
The bombos medallion is a Y-item and one of three magic medallions found in the game.
Location
The bombos medallions is found at an ancient tablet on a cliff overlooking the east side of the Desert. Ordinarily, this ledge is inaccessible in the Light World, and the player will need to head west from the Swamp Palace area in Dark World, pass the hammer pegs, and use the mirror to warp onto this ledge.
Using clips, the bombos tablet can be accessed in Light World.
In order to read the tablet and receive the medallion, Link will need a level 2 sword or greater (Master, Tempered, or Gold) and the Book of Mudora.
Description
Even with the medallion in Link's inventory, it cannot be used if Link is swordless. This is true of the other two medallions as well.
Using bombos creates a huge onscreen explosion at the cost of 32 MP (or 16 MP with the half magic upgrade). This will kill most normal enemies on screen immediately, making it more powerful than the other medallions. Unlike the other two medallions though, bombos is not required to open any dungeons. This means it's almost always skipped in a run unless the goal is 100% or Max% of some kind.
Against Kholdstare, bombos can be used to melt the first phase ice shield. Bombos has no use against bosses other than this.
Glitches and tech
Like other medallions, using an item dash with bombos will arm superspeed.
