They shifted the order of the skills in that line, and the XP per skill is based on where it is in the line. Because of that, impale used to be the 1st skill and had a certain amount of XP assigned, but when it became the 3rd it was internally still 'missing' XP.
Not a problem if you're already using it, but if you ever need to take the skill point out or morph it, you'll first need to gain back the little bit of missing XP for that skill to get it back up.
When I had the bug I wasn't able to just respec the skill at a shrine to resolve it, I ended up equipping a fresh/empty armory build to strip everything, which then let me re-level the base skill to meet its new xp requirement and remorph it.
But now you may be able to use subclassing to drop then reacquire the entire line to remove all the skill points and finish leveling assassin's blade, if you want to remove the lock.
Oh I see, was a skill patch update a few months ago. And it's bugged from which order it was. I get it now. Thanks. Yes it works just was confused why it is also locked. Thanks for the supportive posts.
I wish they could throw a passive fix for this into a patch at some point, I regularly encounter players who are confused about it lol. But as someone once said, it just works, so I guess it's ok.
I had a character affected by this who had Impale morphed. The character had used Impale like that for however long the bug had been present.
I went to a shrine to switch to Killer's Blade. When I removed the skill point from Impale, both Impale and Killer's blade became unavailable to me until I levelled the base ability, Assassin's blade to max level.
This has happened to me twice. First when they rearranged the Nightblade skills a few patches ago and again when I added subclassing to my nightblade. Only this skill too.
My Nb is a 5 star and I’ve had this character for 10 years I HAVE LEVELLED BOTH MORPHS and yet I’ve had to re-level Killers Blade 3 times now on this toon