I think Arcane Blink might need some love and here's my reasoning. The majority of heroes that would normally want to buy Arcane Blink would likely also be buying Octarine Core. But if you have an Octarine and decide to go Arcane Blink, the only benefit you're getting is the cast point increase (which for a ton of heroes truly doesn't matter that much) and a whopping 5% increase in CDR during the buff duration (25% from octarine -> 30% during arcane blink buff). This hardly seems worth purchasing almost ever in this situation.
I think it's CDR should either be increased dramatically (possibly with the buff being a much shorter duration as well). Though this could have balance issues too so perhaps just make this item and only this item's CDR stack multiplicatively with other sources?
Idk it just seems like a really weird purchase if you're not like SF and maybe 1 or 2 other heroes max.