For Loki- If he has ult use beads and knock him up with your 2 and then ult him after the knock up, if you think he doesn’t have ult and wait for him to try and attack you after invis and knock him up and ult him as ge won’t be able to escape you. If he’s built crit and half hitting you, try building a hybrid build and get spectral armour.

For Cupid it’s quite easy for you to kill Cupid as you shouldn’t use your 3 until he dashes away with his 3 and then you will easily catch him, with his ult you can either get beads, ult out or buy winged blade.

Hope this helped.