The sun's core is not hot enough to burn me.

The next user is a person on a boat that who gets stuck between the greek mythologycal monsters Scylla and Charybdis.

6 sides, two monsters; 4 remaining ways to get out.

the next user is set ablaze with very hot flames.

Due to a similar incident that happened earlier in my life, my skin is made of Titanium. The fire doesn't last very long.

The next Person is tied onto the rails of a train about to pass by.

Grammar error: I am tied onto the rails of a train, passing by ___. I choose paradise.

I stick the next person in a universe factory.

no such factories.

the next user is kicked into a black hole

I traverse the wormhole quite easily. (Black holes ---> Wormholes ---> White Holes)

I STAB THE NEXT PERSON QUITE VICIOUSLY WHILE SPEAKING FANCILIY!

I lost 1d4 hit points. I wtill have more than 20 hitpoints and Im still level 1.

Owner of the next message will forget everything, everyone, every memory and every autonomous control. 

I have already reconstructed my personality and thoughts on a computer, essentially becoming an AI. I transfer my conciousness to a body that I had contructed (See SyFy's Eureka, season 5).

I take a new approach and freeze the next user at a temperature of 0K

It turns out that I am an alien lifeform that lives at those kind of temperatures.

I teleport the next user to a magnetar (a rare type of neutron star), where you will be torn apart by both the gravity, and the magnetic field simultaneously.

But.. nothing lives at those tempuratures. Everything is at a standstill, and there is no molecule motion. 0k = absolute zero. Even atoms start to lose their energy.