Idea: Implementation of Lee R, which allows for dead targets to fly and deal damage
Yes, I do know some level of programming, but just a student.
In a way, this is a super method/function meant to replace Lee's current R. I don't know what problems may be caused if the target dies midflight. Originally posted on reddit, with less details.
Function start Let the champion marked be affected by the ult's damage.
A. If the target remains alive, proceed as it currently does. End of function.
B. If dead, then send the corpse flying but only visually. Additionally, produce a hitbox that travels along the path where the corpse goes, which causes the same effect as what would otherwise happen if the champ was alive.
Essentially, produce an invisible Janna tornado with modified parameters so that it I. travels the same path as Lee Sin's target would if it remained alive, II. is travelling at the same speed as his target, if it remained alive, III. deals the damage that Lee's ult would have done if the target was alive, IV: CC duration is set to Lee Sin R's "knock up-upon-collision" duration V. has the same hitbox as his target.
ALTERNATIVE: rather than using a Janna tornado, deploy a "invisible clone" of Lee Sin's target if it will die (with the target's max HP - dmg taken), so that the damage numbers remain easy to calculate, and the clone does indeed receive all of the original effects), and let this clone be used for collisions. At the end of the ult/knockback, remove the clone from the game.
End of function.
As for visuals of the flying corpse... The easiest solution (as in less coding) is to have the corpse's model keep flying, but delay the death animation until the corpse arrives at the end of its knockback.
The first implementation requires only producing a skillshot which has given parameters (CC effects, damage, hitbox shape/size). The second requires a temporary unit with equivalent parameters (with respects to output) as a living Lee Sin R target.
In a way, this reminds me of the good ol' "coded as minion", due to the second one.
Now, if this has already been suggested but turned down (for whatever reason, be it workload or balancing), that would be a bit of a letdown.