So traditionally Mind Spike has been an instant damage no travel time spell in previous iterations of the game, so having this be a travel time spell is a bit awkward, especially when considering how the spell functions and what it does.
Currently the spell is meant to stack 3 times on an enemy and be followed up by a mind blast for a crit bonus. With the travel time you have a few situations with the extended range that it offers in shadow.
So currently you have 4.5 seconds roughly (give or take lag and human error) to get off three mind spikes. And the current cooldown on Mind Blast is either 8 seconds, or down to 5.5 seconds with talents. This means there is always a slight delay of up to 1 second between 3 mind spikes and a mind blast. So there’s this awkward aspect to the rotation with this in mind that leads to little gaps.
But the bigger issue is that because of these little gaps, there’s no real benefit in squeezing out extra mind spikes aside from damage, and with the travel time you can actually clip your mind spike debuff since Mind Blast itself does the damage with no travel time. So you can time a mind blast after your third mind spike and depending on the range the mind blast will hit BEFORE the debuff from mind spike is applied.
This is likely why the original Mind Spike was both zero travel time and a 2 second cast time instead of 1.5, since it offered the cleanest slot into the rotation.
Overall this is fairly minor in the grand scheme of things, but I felt was important to point out how clunky it feels right now if the intention is to test these types of implementations and plan for the future.