I play Muscle and Steel to negate destruction after my opponent targets my personality with a Steel on Steel and he focuses Superior Opponent. Does the attachment still stay in play if my personality loses the duel, or is it destroyed?
Muscle and Steel vs Superior Opponent/Steel on Steel
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.
I play Muscle and Steel to negate destruction after my opponent targets my personality with a Steel on Steel and he focuses Superior Opponent. Does the attachment still stay in play if my personality loses the duel, or is it destroyed?
If your opponent chooses to destroy your attachment with Superior Opponent's Focus Effect, it WOULD still be destroyed.
Muscle and Steel only negates destruction from the action whose targeting it reacted to, which would be Steel on Steel in this case (see From).
So just for clarification, if my opponent targets my unit with Steel on Steel, I react with Muscle and Steel, my opponent focuses Impetuous Challenge and i strike, my unit is still destroyed?
Yes the challenged Personality would be destroyed by the Focus Effect from Impetuous Challenge, because Muscle and Steel will negate the destruction from the effects of the Steel on Steel only, not from the Focus Effects of cards focussed during its duel.