There are several issues with the sounds of Fiend's Grip

1. There are clicking sounds in fiend's_grip_target, at the beginning and at the end. Both are very easy to repair
2. The caster sound is too short for the talent duration. It was not extended.
3. The target sound was extended, but it wrongly includes the caster sound on its extended part.

Fiend's grip's sounds are easy to loop, so why wasnt that done instead? Here are looped versions of the cast and target sounds

(right-click the player and save sound to download them)

I first made the sound play a second time, 5 seconds into the first sound, so there is a smooth transition, then cut the last second of the result off, and then looped the last 5 seconds of the result.

The last 5 seconds of both sounds are looping.

Here is a comparison between the current sounds and the fixed sounds.

PS: I noticed that Dota 2 currently ignores loop ends. If your loop ends somewher in the middle of the sound, Dota will loop from loop start to sound end, instead of from loop start to loop end.