It's so horribly designed it thresholds not even on %HP, but FLAT HP, which also for some reason scales on 3 separate stats; level, bonus AD, and lethality, so it means that it scales into late and gets stronger when Pyke stacks typical AD assassin items. Good luck being executed at half HP.
Better yet, it ignores shield. If your HP checks the threshold test. Kiss goodbye and no amount of shield will save you because reasons.
And it resets! The show never ends! What's next?
And it duplicates kill gold, too! So Pyke can't even run into the gold-sink problem that high kill threat champs are fundamentally balanced by, where they can sit on too much gold they don't even use leading to a starved and lost team, since he basically just duplicates kill gold for his team. Isn't that just lovely...
... And absolutely appalling?