Stealing the Lich King’s weapon causes him to be immune and not able to play cards for the remainder of the game.
https://v.redd.it/2c7o8bb3qu341
It appears that breaking the sword gives its current controller the phase 3 power. Combined with #993, which causes his power to break your stolen sword, the Lich King never advances to phase 3. Perhaps a fitting outcome for someone who hoped to defeat the boss so easily, but since the immunity and inability to play cards is undocumented, it's a bit of a confusing result. Either the sword should impossible to steal, or phase 3 should be initiated by the trigger on the power rather than the death of the sword. The whole fight kinda needs to be reorganized at this point.
(Also bumped #995 and #996 in light of this and other reports.)
https://www.reddit.com/r/hearthstone/comments/e8ut6r/stealing_the_lich_kings_weapon_causes_him_to_be/
It appears that breaking the sword gives its current controller the phase 3 power. Combined with #993, which causes his power to break your stolen sword, the Lich King never advances to phase 3. Perhaps a fitting outcome for someone who hoped to defeat the boss so easily, but since the immunity and inability to play cards is undocumented, it's a bit of a confusing result. Either the sword should impossible to steal, or phase 3 should be initiated by the trigger on the power rather than the death of the sword. The whole fight kinda needs to be reorganized at this point.
(Also bumped #995 and #996 in light of this and other reports.)