Thanatos: Hand of Death is a melee physical assassin, who reaps his opponents with his scythe and selection of deadly abilities.
With Death Scythe Thanatos flings his scythe at opponents to deal damage. Those hit are also slowed, while healing Thanatos. The Scent of Death ability helps with mobility by removing any slow effects and giving a gain to movement speed and physical penetration. And with his ultimate ability, Hovering Death, Thanatos takes to the air before swooping down to damage or instantly kill enemies with a finishing blow, if their health is below a certain threshold. All others are stunned.
A full list of Thantos abilities, plus new skins, voice packs and other changes in the update can be found in the patch notes.