The sword scene, actually, only those with high cultivation can do what Lan Zhan and Wei Wuxian did (the boomerang sword).
Cultivation is considered like a kind of magic from the ancient time, you can become immortal if you keep practicing, that's why in episode 1 and 2 when they are 16 years later, they don't have the look like you've aged... You can cultivate with swords, music (what Lan Zhan's brother did with his flute), spells and talismans
For them, all that happens is more or less their daily life, fly, talisman, incantation
You can find the episodes on Youtube, the subtitle are very good