Tahm Kench story and friends?

I was just in the champ info pages checking out some background stories and came upon Tahm Kench. He has one paragraph about his insatiable appetite and tendencies for devouring the unsuspecting and desperate of Runterra. Then in the friends list it says Aatrox is his friend.

Can we get the story behind this? Is it cause Aatrox is an engine of war and Tahm feeds on those who are desperate?

Who's losing the fight today? Some over confident folk on 5th street Perfect. They'll make a tasty snack as they try to flee.