A Latin equivalent of the English noun 'slayer' is interfector. It's a masculine gender noun. The equivalent is interfectrix if the slayer is female. Another equivalent is homicida, which may be translated as 'murderer' and 'murderess'. It's the Latin noun that's used when the victim is human.
interfector
Intefector(es) deorum
In the spell books
Drago Uccisore
saigo no enjerusureija
you say helmet in latin (casco)<- in latin
Well, I do not know your slayer level, but I can say Slayer is one of the most profitable and exciting skills to train your combat. Slayer is a slow skill so I would be uncertain on how long you are willing to fight monsters. The only way to train Slayer is by getting Slayer tasks from the Slayer masters so try there first. Speaking to the Slayer master in the Edgeville Dungeon should be good for you. If your Slayer level is low then try speaking to the lower-level Slayer masters first and then build up to better ones.
male: horeg (הורג) female: horeget (הורגת)
To say "Who am I?" in Latin you can say "quisnam sum Ego?"
How do you say determined in Latin?
infitialis is the word we say in latin