[quote=“Dungeons and dragons players handbook V3.5”] Purity of Body (Ex): At 5th level, a monk gains immunity to all diseases except for supernatural and magical diseases.[/quote]
[quote=“Dungeons and dragons players handbook V3.5”] Diamond Body (Su): At 11th level, a monk gains immunity to poisons of all kinds.[/quote]
Now in order to be strong enough to break a hordwoodboard Pai Mei must have been at least level 15 (if he had a decent strength score, which its safe to assume he did), and also if he was over a thousand years old he would have had to gain the feat “Extend Life Span” dozens of times:
[quote] EXTENDED LIFE SPAN [EPIC]
Benefit: Add one-half the maximum result of the characterÃ¢â‚¬â„¢s raceÃ¢â‚¬â„¢s maximum age modifier to the characterÃ¢â‚¬â„¢s normal middle age, old, and venerable age categories. Calculate the characterÃ¢â‚¬â„¢s maximum age using the new venerable number. This feat canÃ¢â‚¬â„¢t lower the characterÃ¢â‚¬â„¢s current age category.
Special: A character can gain this feat multiple times. Its effects stack. [/quote]
Now in order to gain this many epic feats its likly that pai-mei is at least level 300-400, meaning that no poison could posibly penetrate his perfect mabotalism.
(Yes, the V3.5 D&D rules do apply in kill bill)