@SMASHING GUY Nope he's just stronger than Eochaid now
Spoiler!
Reread the novel and yes he killed Eochaid only after utilizing Claiomh Solais's full power he even said he can only use it for a few seconds the reason he complemented Korin was because Korin was able to go toe-to-toe against him in pure skill and eventually overpowering him, Eochaid was strong because he was the user of Claiomh Solais in the last iteration but without it he's just a bit weaker against Korin
[Constellation 'Watcher of Light and Darkness' is looking at you.]