"That was close!" Adrian stated but he actually managed to see that attack and even react to it because he used Time Stop.
Adrian knew that the Greater God Amatsu-Mikaboshi will target him first when they come out which is why he teleported the others away from him. He also immediately used Time Stop when he got out and he clearly discovered that the Greater God Amatsu-Mikaboshi is aiming for him. He immediately used Limit Break: Summoner as he reverted the cooldown of this skill earlier before they went inside the Myriad Miles Rivers and Mountains painting.
Inside Time Stop, Adrian summoned all of his soulbounds without missing a beat. Kanlaon reacted faster as he slammed the claw of the Greater God Amatsu-Mikaboshi upwards so that the latter will not hit his master. Adrian ended Time Stop when he saw this happen and the Greater God Amatsu-Mikaboshi actually got caught off balance for a slight second.