Funeral games (FG) find their origin in ancient matriarchal societies. In those societies, the fertility of the relationship between the queen and the king was significant to the fertility of the entire region they governed.
So when the king died, it was of great importance to restore a fertile relationship with the queen. In order to do this, FG were organised as soon as possible. The only goal of these games was finding the best suiting male for this important task. Sport contests were an excellent way of selecting the strongest and healthiest male
When the matriarchal system got gradually replaced by a patriarchal one, the fertility aspect of the FG got replaced as well by a more patriarchal one, honouring the deceased king. This patriarchal form of FG is described in, for instance, Homer's work.
Eventually the FG evolved into the Olympic and other Ancient Games.
<crux> turboke, in your funeral games node you should mention how the Etruscans made slaves fight to the death after their owner died, and how that evolved into gladiatorial combat.