Dumbledore seeing himself and Grindelwald in the Mirror of Erised, cutting their hands During their teenage years, Albus Dumbledore and Gellert Grindelwald made a blood pact where they swore an oath never to fight each other - presumably as a fail-safe to ensure no rift were to set them apart in their grand endeavour
Dumbledore Can't Break The Blood Pact (Yet) We know that, eventually, the Blood Pact between Dumbledore and Grindelwald is broken - because they have their legendary duel in 1945. However, in 1927, Dumbledore is unable to get around the vow he made as a youth to never fight the boy he loved.
JK Rowling has revealed that when Albus looks in the Mirror of Erised, he sees his family, alive, whole and happy (at age about 109). In Crimes of Grindelwald, we saw that Dumbledore saw himself making the blood pact with Gellert.
Attunement Information & Notes Increases the number of Attunement Slots available for Pyromancies, Sorceries, and Miracles. Wearing special rings can increase the number of Attunement slot: The White Seance Ring which grant more Attunement slot by 1. Darkmoon Seance Ring which grant more Attunement slot by 1.
Although Intelligence does not affect pyromancies spells directly, Pyromancies are still classed as Sorcery, and as such will benefit from the damage modifiers of items such as the Bellowing Dragoncrest Ring.