Maybe it's an old wandmaker from a far - off land. This wandmaker has been crafting wands for centuries and has a unique intuition about which wands are meant for which wizards. He sees something special in Harry and presents him with a new wand.
There's a possibility that it's a magical creature. For instance, a phoenix could lead Harry to a new wand. Phoenixes are known for their connection to magic and rebirth. It could have retrieved the wand from a long - lost magical cache and given it to Harry, believing he is the rightful owner.
He could collaborate with Ollivander. Ollivander is the expert in wands, and he has a vast knowledge of wand - making materials and techniques. Working together, they could combine their knowledge to create something truly extraordinary.
In the 'Harry Potter gets a new wand fanfiction', Harry getting a new wand could lead to a whole new set of adventures. He might have to go through a series of trials to fully bond with the wand. The wand could also have a mind of its own, guiding Harry towards certain magical discoveries that were previously unknown. It could also attract unwanted attention from dark wizards who are jealous of its power.
There's a chance that the maker is a new character, an old hermit wizard who lives deep in the Forbidden Forest. He has been observing Harry from afar and realizes that the wands available in the regular market are not sufficient for him. So, he uses his knowledge of forgotten magics to craft a custom wand just for Harry.
It could be Dumbledore. He always had a way of presenting Harry with things that would help him on his journey. Maybe Dumbledore had been holding onto this second wand for a special occasion or because he knew Harry would need it in the future.
The new wand might have a core that is a combination of multiple magical elements. For example, a strand of a unicorn's hair combined with a shard of a powerful magical crystal. This would make the wand extremely versatile, able to channel different types of magic depending on how the wizard holds it and the incantation used.
Maybe an old, reclusive wand - maker who has been waiting for the right wizard to come along. This person could have a special intuition about wands and see something unique in Harry.
Maybe he found a really cool and powerful wand that he thought would be better suited for someone else. So he decided to gift it.
Voldemort could still be the main antagonist. Even with a new wand, Harry is still a threat to him, and Voldemort would be eager to get his hands on such a unique and powerful wand.
An old witch who was once an apprentice to the maker of the Wonder Wand. She could hold many secrets about the wand's construction and powers. Her character could be a bit of a mystery, and she could either help or hinder Harry depending on her own motives.
A character who is a descendant of the original maker of the Elder Wand. They might have an innate connection to the wand and possess knowledge about its secrets that no one else does.