This Fencing Clank was a device built by Gilgamesh Wulfenbach. He designed it to meet the demands of his own swordfighting practice since the typical Student Fencing Clanks are "kind of tame"  and he wants a more realistic practice opponent. He defines "more realistic" for Agatha by if she's ever traveled the Wastelands (foreshadowing her duel with D'Omas's rogue Spider Clank). Agatha agrees with his reasoning after a bit of thought.
Unfortunately (in a way), whilst complaining about Zulenna's reaction to her existence, Agatha activates the clank by pressing the heart-shaped button (a traditional fencing target) in the middle of the clank's torso. The clank promptly whirrs to deadly life, resembling a mechanical Kali as much as anything. Gil starts defending the traditional way; Agatha thinks outside the proverbial box and as easily as she turned it on.
However, there's a 43% automatic restart chance - an extra challenge for Gil (or whichever opponent it might face). In this case, Agatha is challenged as the clank has already learned to defend itself against her special non-fencing-enabled attacks, and she has to go yet further outside the box . After she shuts it down a second time, in a comment with an uncanny echo to a later thought of Othar Tryggvassen's , Agatha amusedly accuses Gil of being upset with her more for the fact that she beat the clank untraditionally when he had already admitted he was at his fighting it. His counter-accusation of her executing poor laboratory procedure seems weak in response.
Agatha does admire Gil's clever work on the device, no matter who turned what on or off. The ability of the clank to learn by experience impressed her the most; this is a common challenge in artificial intelligence work, whether it's driven by steam and gears, positronic circuitry or conductive materials embedded in silicon.
Alas for the Fencing Clank, it was not long for this world, as the next time Agatha slipped into a Spark-driven sleepwalking building frenzy, she transformed it with Gil's help into the Rescue Clank instead.