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, 24 January 2014
Suppose I have a Shugenja at home, am playing Rae Sensei, and that shugenja has Sailor's Warning and Steal the Candle's Flame equipped.
I now go to battle with my handy dandy arrow-absorbing Yojimbo, leaving the Shuggie at home. Eventually during the battle, I use Sailor's Warning, targeting my Yojimbo, and an enemy personality.
Can I interrupt it with Steal the Candle's Flame to give it +2 strength?
What if it Steal the Candles Flame was Expert Archers, could that interrupt Sailor's Warning and give it +2 strength?
A player, 24 January 2014
Rae Sensei says: Actions on your Spells have Home if you target your Samurai with them.
With Sailor's Warning this works fine, because you can target the Samurai, so the ability becomes Home.
Steal the Candle's Flame is another issue, though, because nowhere do its abilities target your Personality. Therefore, the spell can't gain Home via Rae Sensei. Since Interrupts are subject to the Rule of Location, it is not legal to react with a Steal the Candle's Flame attached to a shugenja at home.
What if it Steal the Candles Flame was Expert Archers, could that interrupt Sailor's Warning and give it +2 strength?
I'm not sure I understand this. Expert Archers create a RA 3, not 2.
In any case Expert Archers must be at the current battlefield if you want to use the ability for anything, including combining. It doesn't "inherit" the Home keyword from the spell.