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, 1 March 2013
Greetings! I always thought that effects that created additional actions resolved right away but had a delayed effect of letting the player have an additional action. But, From here: http://www.l5r.com/forum/viewtopic.php?f=59&t=102081&sid=ba59669be67ca9c1dac0bc545cdbc337
Its not so clear . Is it legal for me to 1.) Play Grappling the Snake 2.) With grappling the snake's additional action, i use a non-kiho action.. say something like steel on steel. 3.) not surprisingly my opponent had a delay clan virtue (lets say duty of the crab) which he focused. So his personality does not die, so can i then react with pillars of virtue from my earlier grappling the snake to play another steel on steel?
Thanks.
A player, 2 March 2013
I have retracted the ruling, so it should be clearer now.
However, my ruling from the linked source was slightly different from the situation you suggest, in that the additional action was granted by a Reaction (Without Mercy) instead of a Battle action (Grappling the Snake), so timing could be different here since the rules on additional actions refer to granting them during the resolution of non-Reaction actions.
In any case, you have to react with Pillars of Virtue before taking the additional action granted by Grappling the Snake.