Many-Faced God

"What do we say to the God of Death? Not today."

- Syrio Forel and Arya Stark

The God of Death is a deity worshiped in the Free City of Bravos.

Season 1
Syrio Forel preaches his faith in the God of Death to Arya Stark during their dancing lessons.

In the books
In the A Song of Ice and Fire novels, the God of Death is referred to as the "Many-Faced God", or "Him of Many Faces", and is worshiped by the Faceless Men: a guild of assassins based out of the Free City of Bravos.

The Faceless Men believe that the Many-Faced God is unknowingly worshiped by most faiths, simply under different names.

In A Clash of Kings Jaqen H'ghar informs Arya that she must name three people for assassination in order to atone for saving his life, as well as those of Rorge and Biter, which subsequently robbed the Many-Faced God of his dues. This is changed somewhat in the TV series, where Jaqen claims that the debt is owed to the Lord of Light, whom he refers to as the "Red God". The reason for this change is unknown.