Indeed, Alexi Ethren had feelings for his master. However, those were feelings that he didn't dare act upon as there was a master-disciple relationship between them.
Hence, he wanted to wait, wait till they had their revenge, and then perhaps he felt that he could provide her warmth even if she was going to die soon because of her waning lifespan. He always wanted to see a smile on that cold face which he didn't know that it was disguised until now.
He couldn't help but forcefully try to smile at his mother's sleeping face. His lips quivered as he propped her up to face him straight.
"Master..." He endearingly called out as mentioned in the letter.
But still, it garnered no attention from his mother as she lay in his arms like a corpse. He felt that even her warm body was starting to become cold.
"I'm not letting you die! I'm not reading the fourth scroll! I know that you have written your last words on the fourth scroll but I'm not ready!"