I was playing prison and i was at the black market and saw someone hit a guy who had port4 armor i have enchantments clients where i can see the enchantments on armor and swords but is it even possible to get this kinda of sword ????
It is possible to enchant protection 4. (/warp enchant) Just to let you know, you cannot enchant protection 4 on a sword.
I don't think any of the admins (meaning staff) would let a sharp X sword out into the world. It's too dangerous.
In Prison there is currently no Sharpness 10 swords. I doubt there would ever be. This may be a client side glitch or you must be imaging it.