Bond of the Blaze
The Bond of the Blaze, also known as Flame Liberator (フレイムリベレーター, Fureimu Riberētā?) or Lea's Keyblade (リアのキーブレード, Ria no Kīburēdo?), is the default form of Lea's Keyblade that appears in Kingdom Hearts 3D: Dream Drop Distance and Kingdom Hearts III.
Kingdom Hearts 3D: Dream Drop Distance
Lea requests to become a Keyblade wielder under Yen Sid in order to help Sora and Riku in their battle against Master Xehanort. Yen Sid accepts, but as they are short of time, has Merlin, Flora, Fauna, and Merryweather suppress the time needed for Lea to train. Lea eventually manages to summon the Bond of the Blaze, but does not get the hang of doing it reliably until after Sora has been rescued from Master Xehanort. Having learned to summon the weapon voluntarily, he playfully vows to become Riku's rival and a future Keyblade Master.
Kingdom Hearts III
Lea continues his training with his new Keyblade, learning how to Formchange it back and forth with his chakrams. During his fight in the Keyblade Graveyard, it is revealed that Lea's control over his Keyblade is still lacking somewhat, as Xemnas is able to force it to vanish briefly. However, he is quickly able to resummon it to help Roxas and Xion take the Recusant's Sigil back from Xemnas.
The guard of the Bond of the Blaze resembles the Eternal Flames chakrams, as well as the guard of the Bond of Flame Keyblade, with a straight hilt rather than a cross-shaped handle. The blade and teeth take the shape of a glowing translucent streak of yellow-orange flames, resembling those of the Frolic Flame; however, the teeth of the Bond of the Blaze form the shape of a hook, rather than a closed loop. The Keyblade's chain links resemble the Eternal Flames; the token also resembles a pure silver version of the weapons.
In Kingdom Hearts III, the blade has a constant flowing flame effect.
Lea can Formchange the Bond of the Blaze into his chakrams at will.
The Bond of the Blaze's name references the Bond of Flame Keyblade, and Lea's affinity for fire. Flame Liberator also references Lea's affinity for fire, as well as his desire to free his friends from their fates.