Louis Tac is one of the main protagonists and a part of the main group of survivors throughout the series.
He and the kids are traveling from Emon to Lans in hopes to find shelter at a monster lookout camp from the war taking place. He was the only adult in the group and would act as their guardian until Yan and May later joined.

Copy magic:
Allows the user to “copy ‘n’ paste” someone’s magic abilities to use it as their own.

• Tac hated being called ‘Louis’. He preferred being called by his last name.

• ‘Tac’ is ‘Cat’ written backwards.

• He owned a restaurant called ‘Chez Tac’s Restaurant’ which was previously owned by his father.

• The fact of him being a black cat references ED_7’s cat who was also a black cat.

• Tac once worked in the army for a few years, but left due to the death of his brother.

• Louis was killed off because his magic was a big threat to the humans.