Obsidian Halls of the Lost

Legend of the Five Rings card from Lotus Edition, Code of Bushido

Card Type: Stronghold
Province Strength: 8
Gold Production: 4
Starting Family Honor: -19
Clan: Shadowlands
Keywords: Obsidian
Card Text: You do not gain or lose Honor; this is not negation.
You may not take Political actions or actions that cause other players unconditional Honor losses.
Limited: Bow your target performing Shugenja. Target a Personality. His controller decides whether this action permanently gives him Shadowlands or if it gives him a -4C token after your next turn begins.
Reaction: After an attack is declared, target a Shadowlands Personality without the printed Shadowlands keyword. He may not assign, and will not move, to battlefields this Attack Phase.
Legality: Age of Enlightenment (Lotus), Rain of Blood (Diamond)
Deck: Pre-Game

Printings

Erratum: Reads, "Obsidian Halls of the Lost 8PS 4GP -19FH Limited: Target and bow a Shugenja you control: Target a Personality. His controller decides whether this gives him the Shadowlands trait permanently now or a –4C token when your next turn begins. Reaction: After an attack is declared: Target a Shadowlands Personality without the printed Shadowlands trait. He may not assign or move to battlefields this attack." [MRP, Lotus Edition, 31 October 2005] Rules Archive, August 18, 2007, p. 150

Q: With Obsidian Halls of the lost: My opponent can't choose to give their character Shadowlands if their character already has Shadowlands, correct? I feel like I remember that being a thing, but I'm also not sure I could articulate why it's a thing...
A: No, your opponent can totally choose to give them Shadowlands even if they already have it. You can't just nuke tainted people's Chi with the box; you'll need other ways to make it a bad choice. Brook Cunningham, "Sun and Moon #rules-questions", 12 May 2024