Incoming Trouble.

"A common tree?! How did she reach such an unfathomable size then?"

Felix couldn't imagine a normal tree turning into a cosmic entity with the size of half a galaxy.

"By using photosynthesis just like any other plant." Lady Sphinx answered, "Though, in the case of Lady Yggdrasil, she absorbs light directly from stars and other nutrition from planets."

"Is there a limit to her growth?" 

"As far as know, there isn't." Lady Sphinx replied, "Theoretically, she can grow as big as the universe if she had enough sunlight and nutrition."

"I see."

Felix understood that it might be theoretically possible but in practice, there was no way it could be achieved.

The fact that Lady Yggdrasil had already reached this size was already an unimaginable phenomenon.

Just like any other creature, growing isn't the only thing that needed nutrition.