At the beginning of Deadly Promise, Jedo levitates out of a dimensional portal that appears out of thin air. He then unfolds his wings to reveal a skeleton-like body and summons forthe a large scythe that he grabs and raises over his head before slashing through all enemies on the field. This causes the enemies to explode and die instantly.
- Deadly Promise can only be used after obtaining the Dark Stone from West Voz Forest and turning it into a Dark Talisman by giving it to Zalan in Jeremi.
- Deadly Promise can instantly kill all random battle enemies, Seru or otherwise, as well as the hidden boss Lapis. However, it does not instantly kill boss enemies. When used against a boss enemy it will usually do half the damage of other Ra-Seru summons.
- At the end of Deadly Promise, the image of the Grim Reaper can be seen in the shards of the fallen enemies