A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 24 December 2009
So I was quite pleased with myself for dropping the "Last One" on a personality with 2 "Chrysanthemum Blossoms", "The Hand of the Obsidian Dragon", and the "Armor of the Ryu". This was an actual tournament game against a dishonor deck, and the "cannot be dishonored" part had me pretty confident of a quick victory if I never put another personality out. Then he got some active judging about Kurimi on the same turn he flipped Whispers of the Dying Sun(I am not making any of this up.) So my big guy dies of Chi death and now I have 0 personalities against a dishonor deck, and the game ended painfully about 45 minutes later.
Just to be clear, does he die from 0 chi, or does the last -1 chi token not land because of the wording of "The Last One?"
Last One Open: Target your Personality: Destroy all of your other Personalities. If this destroyed at least four Personalities, permanently give your targeted Personality +4F, and until the end of the game, negate effects of other player's actions that bow, dishonor, move, or destroy him.
Bayushi Kurimi EXP Political Limited: Bow Kurumi: Target a Personality. His controller may dishonor him. If he is now honorable, give him two -1F/-1C Seduction tokens.
Thanks.
A player, 26 December 2009
does he die from 0 chi[?]
Yes.
If the Personality who performed The Last One gets enough Seduction tokens from Bayushi Kurimi (Experienced) to reduce his Chi to zero, he is destroyed and The Last One fails to negate this destruction because its negation effect is ongoing (see below, emphasis mine).
Negating conditional ongoing occurrences: "EXCEPTION: Special rules apply to the prevention of Personality destruction from zero Chi (see Chi death rule) and other continuously applied destruction effects. Ongoing [...] effects that prevent destruction [...] will not prevent destruction from such an effect. Only a continuous prevention effect (for example, "This Personality will not be destroyed" as a trait), or an effect that specifically refers to the zero Chi rule (for example, "Until the end of the turn, he will not be destroyed for having 0 Chi") can overcome the Personality's destruction."