Pantheons passive says it blocks the next tower hit or basic attack. Today i found out that it blocks gangplank's Q if it does not crit. so ya.. make me an adjucator or wrenchman.. whatever that helps with finding glitches

Everything that says it applies "on-hit effects" (like GP's Q) counts as a basic attack for pretty much all intents and purposes, so... this is working as intended? Or are you saying it specifically does not block the Q if the Q crits?

yup it can block ezreals q and many other abilities

It also blocks Monkey King crushing blow (Q)
And I've noticed something (Glitch? Meant to be?), If you make an auto-attack and use Q RIGHT when it lands, it blocks both.

It blocks fiora's ult