Although gaining Powers by oneself is possible, there is another way to do it with Creatures. Contracting is the act of signing a Contract that grants one Powers in exchange for something a Creature desires.
Contracting—although the simplist way to gain Powers without needing to do Experiments—can be very dangerous, especially when it’s involving a dangerous Creature. For example, a Daemin may give you its Daeminic Fire, but it may take your love one in exchange. Contracts can also be broken at any time by the Creature, meaning that they can de-power a Mortal without needing to give anything back.
This method is also the reason for the existence of the Esoterical Power Category, as a Creature can grant one Powers of its kind. A Spectre, for example, can give a Human access to Intangibility and Possession.
Almost all Creatures can create Contracts, as the Superomena gave them all intelligence and the ability to understand Humanity. But it’s still a potentially dangerous path, especially if one decides to break the Contract behind the Creature’s back.