Aleron actually wanted to disappear at this moment and enter the secret realm, but a strange feeling gripped his heart and he figured out why.
Because even if he decided to escape and teleport into his Eldertide Archipelago, he would still be slower than Demon Lord Narazar's attack, that tiny orb in front of his finger.
The moment he activated the rune, and initiated teleport to enter the portal, he would be struck by Narazar's attack before entering.
Narazar wanted Aleron to attempt escape because if Aleron did that, his control over the barrier would decrease by splitting his focus in that brief moment and he would be able to inflict more severe damage on Aleron.
Fortunately, Aleron also realized the trick and stood his ground, his focus entirely on his defense. Only after Narazar attacked and he survived would be able to enter the secret realm.