I don't quite remember if it's a reincarnation story, but it is a story based in a fantasy world.
The scene I remember from the manga is where the mc tries to buy scrolls to learn magic, but the shop he is introduced to only sells scrolls to those she deem worthy. The shopkeeper is a tiny elf magician who is known as a genius, capable of using more elements than most people (or everyone, maybe it was 6 elements), and she decides to test out mc's magic ability.
He is tested to be able to use all (8?) types of magic, and when he tries out a weak fire magic (flare I think it was called?) to light a candle as the elf told him to do so, instead of lighting the candle as normal, he brings forth an enormous pillar of fire onto the candle.
As well, everytime mc surprises the elf genius with his aptitude of all elements and his magical output, the elf shakes (it looks like she's vibrating violently) in shock.