Kefka Vs. Terra
Here's the dirt on how these objects relate to one another:
Kefka controls Terra using the slave-crown and uses her as a weapon of mass destruction, until the incident at Narshe jars her out of it. Kefka pursues Terra after this, personally appearing at Figaro and almost single-handedly attacking the castle in an attempt to get his hands back on her.
Later in the game, Kefka plays chessmaster and uses Terra twice, first to open the Sealed Gate and second to lure a bunch of Espers into Thamasa. After this, though, he seems to lose all interest in her (probably because with all the power he gains in Thamasa, he has no more need for her).
If Terra is present in the final boss battle against Kefka, she has special hardcoded enhanced power against him.
Later in the game, Kefka plays chessmaster and uses Terra twice, first to open the Sealed Gate and second to lure a bunch of Espers into Thamasa. After this, though, he seems to lose all interest in her (probably because with all the power he gains in Thamasa, he has no more need for her).
If Terra is present in the final boss battle against Kefka, she has special hardcoded enhanced power against him.
Metrics
Race Kefka: magitek-infused human. Terra: half esper.
Hometown Kefka: Vector. Terra: Vector.
Sex Kefka: male. Terra: female.
Race Kefka: magitek-infused human. Terra: half esper.
Hometown Kefka: Vector. Terra: Vector.
Sex Kefka: male. Terra: female.