Portal gun

Summary
Portal gun is one of the weapons that has weak damage but has the ability to teleport

Analysis
Portal gun's main skill: Shoots bullets and after a medium range creates a portal, after firing the second bullet creates two portals with a black background, which will teleport between those two portals. Enemies entering that portal will lose some HP. After a while the portal will disappear.

Tips
Thanks to the teleport skill, you can put one bullet in void, then fire a second bullet right next to the enemy, they will be teleported to void and you win.

When you are about to fall into the void, which has a portal on the ground, then you should shoot one directly below you, then you will hit the portal and be safe.