What happens when Lee Sin uses Resonating Strike on a Vlad using Sanguine Pool?
Solution 1:
Lee will be teleported to Vlad, but will not damage him. Works the same as twisted advance, Maokai will be teleported to Vlad location, but will not deals any damage.
Solution 2:
It seems from that LoL forum thread [1] that once Lee Sin has a lock on a target, he can dash to him even if he became untargetable, thanks to the lock. This does make the damage unless the enemy champion abilities cancel received damage.
In the detailed abilities on wikia [2] and [3] we can read that
Resonating Strike is the follow-up ability to Sonic Wave. If Sonic Wave has hit a target, Lee Sin will be able to charge them while they are revealed, dealing physical damage and an additional amoung of damage equal to 10% of their missing health.
Morgana's Black Shield does not block Sonic Wave nor Resonating Strike, but Resonating strike can be blocked by other spell shields.
No patch note ever noticed that this has been corrected so far (V1.0.0.135) so it should be the same at the moment.