Retlon Brenclog isn't on instant respawn.
 

Retlon Brenclog in crushbone originally spawned as soon as he was killed. As I can tell, he has a typical respawn time as well as a place-holder.

Need supplementary evidence or research as I am not familiar with this.

http://everquest.allakhazam.com/db/n...98143261728781

http://everquest.allakhazam.com/db/n...=354&p=3#m6983

http://everquest.allakhazam.com/db/n...=354&p=3#m1567

http://everquest.allakhazam.com/db/n...98205906128672

http://everquest.allakhazam.com/db/n...98153040822021

Several other posts after 2001 refer to this as well.

As for not having a placeholder, I believe it is indicative of the fact that he immediately respawns upon death.