What is the relationship between Odin, Seifer and the Kanji that appears? in Final Fantasy VIII, if you have the Odin GF (i don't know if this still happens if you don't have him, i always got him), when you go to fight Seifer at the end of Disk 3, Odin appears. generally when this happens he comes in with Zantetsuken and kills all the enemies, never works in a boss battle except in this scripted sequence where Seifer kills Odin.

When Odin appears and kills enemies there is 3 Kanji that appear, each one appearing by itself as the scene of the strike is replied but when Seifer kills Odin there is a forth Kanji while Gilgamesh (who also uses Zantetsuken replacing Odin) shows nothing

So i am wondering, what is the relationship between Odin, Seifer and the Kanji that appears when they attack?
The kanji that appears when Odin uses his special attack is 斬鉄剣 (Zantetsuken).

However, when Seifer kills Odin, it shows 斬鉄剣返し (Zantetsuken-gaeshi) which literally means "Zantetsuken Reversal". -(k/g)aeshi is a common suffix to mean "reversal/counter", especially in martial arts like Judo (e.g. Tsubame-gaeshi).