What is the ruling on one who repents after having harbored the intention to kill, and what is the legal ruling for intentional and unintentional killing?

The act of killing a soul that Allah has forbidden, except by right, is a crime and one of the gravest major sins, as Allah Almighty says: "And they do not kill the soul which Allah has forbidden, except by right," and "And whoever kills a believer intentionally - his recompense is Hell, wherein he will abide eternally, and Allah has become angry with him and has cursed him and has prepared for him a great punishment." As for intending to kill but not carrying it out, it is considered a sin and recorded as a misdeed, unless it was abandoned out of fear of Allah, in which case it is recorded as a good deed. Plotting to kill and intending it is a great sin, and a Muslim must repent from it.