"BY INFERNO'S LIGHT" is correct!!!
To explain...
Satisfaction is not enough... Worf keeps fighting, even though Martok and Ikat'ika tell him honor is satisfied.
Another form of training... Ikat'ita tells the other Jem'Hadar to observe, analyze, and remember the fights with Worf, which is their sessions of training.
A runabout is used... the Bashir Changeling uses the Yukon to try to blow up the Bajoran sun, and Worf and company use their runabout to escape.
Victory is not always life... Ikat'ita yields, giving Worf that victory, but the Vorta tells the other Jem'Hadar to shoot them both. Had Garak not made that connection work in that split second, Worf would have died.
A pillar in this community... the lighted pillars are touched when any fighter hits the ground so it shows they are still in the fight.
A lot of purple... a fleet of Jem'Hadar ships comes through the wormhole. The ships are purple.
Appearances are deceiving... the Bashir Changeling fooled everyone for weeks. Only the signal from the Gamma Quadrant clued them in.
Unexpected allies... the Romulans show up with the fleet to make a stand.
Lights out... the light Garak was using goes out and causes his panic attack.
I was hoping it would take 10 clues before someone got it, but 9 is acceptable. This is the longest streak of clues for one of my episodes.
Your turn, JP