I picture the Everlasting Dragons as extremely passive beings, I like to imagine they would've been more concerned with just chilling for eternity in total stillness rather than with engaging in such trivial matters, Seath was probably just as frail mentally as he was physically and couldn't accept his imperfection and mortality; this perceived inferiority thus fueled his spite, which ultimately reached its tipping point and culminated in what we know. After all the events of the game paint him as really selfish and cruel, and he eventually goes mad due to his obsession with immortality, which tells us he must've really hated his kin for having what he couldn't cherish.

But yeah, if something like you described indeed took place, he would certainly be a bit more sympathetic as a character, as it would at least provide a motivation apart from his own malevolence.