Regarding this ruling then, applying it to Strike the Summit, Strike the Center, and Strike the Base chain, if the opposing player had a Gate Guardsman, would the additional action have to wait until the reactions (from the 2nd and 3rd kihos mentioned) are finished resolving or would it be able to wiggle in between Strike the Summit and Strike the Center?
re:East Hub vs. Gate Guardsman applied to reactions
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.
Kiho Battle: Bow one of your Rings and target one of your unbowed Monks: Move home a target Personality opposing him. Bow the Personality if he moved. You may discard a card: If you do, search your deck for a Strike the Center, show it, and put it in your hand.
So before Strike the Summit has completely Resolved the player taking the Action has gotten the chance to add Strike the Center to his hand.
Now comes the chance to play Reactions "after resolving" Strike the Summit. The Active Player goes first and then it continues around the table in Turn Order.
If the Active Player is the one who controls Gate Guardsman, he can play the Reaction. The Additional opportunity to take a Battle Action becomes a Delayed Trigger that will resolve later.
Now the player with Strike the Center can play it as a Reaction and get Strike the Base.
Again, the Active Plater gets first Reaction to Strike the Center resolving and it passes in Turn Order.
The player with Strike the Base plays it as a Reaction.
Again, the Active Plater gets first Reaction to Strike the Center resolving and it passes in Turn Order.
Everybody passes a whole lot.
Once there are no further Reactions to the original Battle Action (Strike the Summit), the controller of Gate Guardsman takes his additional Battle Action.
Now, if the player of Strike the Summit were the Active player, he'd effectively be able to play his enter Strike Chain before Gate Guardsman ever got to React to Strike the Summit.
Either way the additional Action from Gate Guardsman isn't going to break up the Strike Chain.
For What It's Worth: take this ruling as Tentative for now. I'm going to discuss the implications in greater detail with the whole Rules Team to make sure we're all comfortable with this.
Ideally we want it to be obvious when additional Battle Actions get played, but we don't want to create weird spirals of Battle Actions inside Reaction Windows of Battle Actions inside Reaction Windows, you know? Nor do we want to deal with conflicts of delayed Additional Battle Action triggers preempting Reactions "after resolving a battle action" that grant such Additional Battle Actions themselves.
- Marty Lund Deputy Rules Monkey