Fate/Zero Season 1 Episode 13

The Forbidden Banquet

Waver has a dream of Rider's past in his search for Oceanus before waking up. Caster and Uryū returns to their lair and are mad to see their "artwork" destroyed by the fire. But Uryū soon cheers up Caster by telling him his twisted logic that God, who Caster hates the most for Jeanne's death, is just a spectator who enjoys seeing humans do whatever they want. Impressed by his master idea, Caster plans a "grand spectacle" for God. Meanwhile, Waver and Rider go shopping where Waver has second thoughts about being Rider's master. As they head home, Rider learns about Waver's problem but gives him some words encouragement for him to not look down on himself. Suddenly, Waver and Rider detects something at the city's river where Saber and Iri arrive to see Caster turning himself into a giant demonic monster. Realizing the threat he pose, Rider has inform the other contestants and they all agree on a temporary alliance to stop Caster before his monster attacks the city and kill the civilians. With Rider leading the vanguard, Saber joins him to allow Lancer an opening to use his spears to target Caster.