Is it permissible to name a male newborn "Malik," even though there is an opinion that it is the name of the custodian of Hellfire? And is it permissible to name him "Ayan" (without a shaddah on the yaa’)? What is the advice regarding choosing names for children from the Qur’an and Hadith?

The name "Malik" is a good name and permissible to use. The fact that the guardian of Hellfire is named "Malik" does not make it objectionable, as he is an angel from among the angels of the Most Merciful. As for the name "Ayan," it appears to be a foreign name, and it is not advisable to use it if the newborn is Arab. Good names should be chosen for the newborn, especially those favored by the Shariah, such as "Abdullah" and "Abdul Rahman," and the names of the prophets. Names that imply servitude to other than Allah or self-praise should be avoided. The basic principle in naming is permissibility, unless there is a Shariah text prohibiting it.