To me Grasp seems to be extremely good in laning phase, but underperforming outside of that
Obviously this has to be with being able to stack it on minions during laning phase, but also the fact that teamfights happen so fast that 4 seconds for it to prime is way too long for the reward it gives you, compared to something like conquerer that is.
I propose a simple change that'll make it useful once you leave laning phase, make it so past level 11 the time needed to prime Grasp is 2 seconds instead of 4. This way you'll be able to utilize it a lot more during team fights and late game duels, and might even spawn some actual "undying" situations.
or
is capable of stacking Grasp to 20+ during the laning phase, and that results in 100 health and nothing else.
Not really that strong