Odin's powered-up form. His improved skills increase his chances of decimating foes.
Raiden appears very similarly to Odin, though he is mostly colored in blue with gold highlights on his armor and a blue cape. He is a tall knight who rides a mostly blue and white horse.
Raiden costs 80 MP to summon. His ability is Shin-Zantetsuken (or True Edge in the original translation), which inflicts Death to all opponents. It has a Hit Rate of 140, works against undead enemies, and will stall an enemy's Final Attack one turn but it will fail on targets immune to Death.
In the original releases, Odin is the only magicite that provides a stat boost to Speed, while Raiden is the only esper that provided the Quick spell. Therefore, many players may choose not to upgrade Odin to upgrade Speed, at the cost of the Quick spell. However, in the Advance and subsequent releases, new added magicite also provide a +2 Speed boost (though others also teach Quick). Players therefore may feel more comfortable upgrading Odin to Raiden.
Raijin, also called Raiden, is a god of thunder and lightning in Japanese mythology.Raiden is the Chinese/Japanese word for the physical phenomena thunder and lightning.
The Japanese word Raiden (雷電?) is written ライデン? in katakana. The summon's name is instead ライディーン (Raidīn?). One possible source for this name is that it is a mix of "Raiden" with "Odin": In Final Fantasy VI Odin (オーディン, Ōdin?) does not extend the ディ (di?) sound, however there are other times in the series Odin's name has been written オーディーン (Ōdīn?).
There is a 1976 anime series called Brave Raideen where the titular mecha is named Raideen (ライディーン, Raidīn?). Yellow Magic Orchestra has a track called "Rydeen" from the 1979 album Solid State Survivor. The track is known for having been sampled and covered in many early Japanese video games, and drew inspiration from the rhythms of a running horse. The name for the track has been officially transcribed into Japanese as ライディーン (Raidīn?) (and also as 雷電?, the same kanji for Raiden).