Humility gets rid of all abilities. It is a static ability that is always on. There is never a point in time that a creature on the battlefield that it is not affected by humility.
When Acidic Slime enters the battlefield, Humility has stripped its abilities. It has no abilities to trigger, so it does nothing.
The GJ way path to no lynching:
When Acidic Slime enters the battlefield, Humility has stripped its abilities. It has no abilities to trigger, so it does nothing.
Acidic Slime will never destroy humility.
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