Bab 216: The Two Mysterious Friends

From its explanation, the System mentioned that the leaking essence was actually now wasted and was actually absorbed by his two 'friends'. 

At first, Ban naturally thought that the System was referring to Eva and Tria as his friends, but upon thinking about it deeply, he recalled that the System never called Eva as his friend, and instead, it preferred to call Eva as 'Contracted Beast Eva', or 'Summoned Beast, Eva'. 

So he suspected that the System might be referring to something or someone else when it mentioned 'friends'. 

Ban was actually suspicious about it, as far as he knew, he doesn't really have any friends.

Although Kuys, Eva and others can be considered as his friends, he always referred them as his family, and not just some mere friends.