A vex is a small flying wisp-like hostile mob that can phase through walls and wield a sword. They are only summoned by evokers as an attack. When aggravated, they start glowing red and will lunge at their target, following them through walls and other solid blocks. Vexes can spawn only by an evoker summoning them as an attack or in Creative mode by summoning them with an egg.
Vexes spawn when an evoker summons them as one of its attacks. When a vex is being summoned, the evoker is surrounded by smoke and a magical, horn-like sound, after which a group of three vexes will appear around the evoker. The vexes have a lifespan of between 30 and 119 seconds before dying. Additional vexes can be summoned by the evoker if some are still alive from the previous summoning. Vexes will never spawn naturally, although they can be spawned with spawn eggs or summoned using commands.
Vexes will attack players, adult villagers, wandering traders, and iron golems when summoned by an evoker. They have the ability to fly and phase through walls and blocks including lava and water without taking damage.
When they attack a player or a mob they will start glowing red and lunge at their target. If a vex is attacked, all other vexes in the area will become hostile toward the attacker as well. After killing its target, the vex will become idle and wander around in the 15x11x15 cuboid range with the evoker being at its center.
When killed by a player or a tamed wolf, vexes will drop 5 experience orbs. In the Java edition, the vex will not drop its iron sword, but in the Bedrock edition, the vex drops its sword with random durability. The chances of the drop and durability of the sword are not affected by the looting enchantment.
A. After killing the evoker, you can feed the vex beetroot and it will become friendly. It will follow you around and attack hostile mobs with and for you as well.
A. Yes, vexes are not hindered by solid blocks. They can fly through walls, trees, and even the ground itself.
A. By giving them a name or taming them, you can stop them from despawning.
While vexes can be dangerous if you are unaware of their whereabouts, they are not difficult to deal with and they don't deal too much damage. But they are a good addition to the game as they make the evokers an enemy you cannot ignore or take lightly, thus providing a challenging experience.