If the Tomb Guardian were present, he should have appeared the moment Master Owen and the others entered the Nirvana Grand Tomb. Santa had been secretly observing them for a long time before coming into contact with them. He should be considering leaving the Nirvana Grand Tomb with Master Owen before fully awakening and getting a head start on understanding this era.
The reason he needed Master Owen to take him out was precisely because of the reasons Master Owen had previously persuaded him. An Innate Spirit controlled by divine sense cannot boast of being invincible. He would face many dangers. With the protection, or rather the cover, from the Horizon Bureau, safety would be greatly increased.
That's why Master Owen wanted to send someone to serve Santa, who only hesitated a moment before agreeing.
