The talent that the Wood Vessel Sigil technique took was the Plant Affinity and Communications talent, while the talent that the Lightning Vessel Sigil technique took was the Lightning Call talent.
These two talents aren't gone. They have just been upgraded. This upgrade process is why only those who have cultivated the Everlasting Wood Art and Divine Lightning Armament technique are the ones who can use the two vessel sigil techniques.
Only those who cultivated the Everlasting Wood Art and used it to create their foundation will get the Plant Affinity and Communication talent. Therefore, other cultivators who established their foundation with other cultivation techniques won't be able to use the Wood Vessel Sigil technique. The same goes for the Lightning Vessel Sigil technique.
Since he met all of the requirements to use the two vessel sigil techniques, once he learned them, his talent was taken and transformed into a mark on his head.
