Here are some more conventional Picks that Pyke could Pair well with:
Is the first pick that comes to mind, with how much damage and cc Pyke bring coupled with how much damage Draven can do early and later on, the two are going to be a devastating duo to have to deal with, additionally, they could snowball very hard with Draven's passive and Pyke's ultimate.
Also comes to mind, She could throw Pyke into the middle of a fight, where he could easily tear up enemies with his E and R, additionally, Kalista now suffers from a shorter range compared to other adc's but Pyke can pull people closer to make this less of an issue.
This could work due to how much burst damage the two could do, the way I see it is Jhin preps a 4th shot, Pyke stuns an enemy, Jhin roots them and fires a grenade along with the 4th shot, if this take them low enough, Pyke could go in for the execute and infuse them off.
Now for a few.....less conventional pairs.
Morde Lacks range, being a melee Adc is rough, But Pyke can fix this, With Mord's W and Pyke stun and pull, the two can deal heavy damage to whoever they can get close to, perhaps bursting people with little to no time to react.
This would be wired, but it could work, the amount of sheer Cc these two bring are scary, plus a double hook should scare anyone, but now, Pyke bring massive amounts of Burst and engage that, when coupled with an ap blitz, could destroy any botlane.
Oh boy, this is fun. Both of them have Executes, so if one misses theirs, the other can make up for it, Also the combo's with Urgot's E and Pyke's Q can force any adc so far out of position that they might not be able to recover.