First an explanation on what an OT3 is, for the folks who may not be familiar with fan jargon. Let us start with its origin. OTP is an acronym for One True Pairing. A “One True Pairing” is a couple you are extremely fond of, a pairing you think of as being in a relationship, even if the characters are not in a relationship in canon. Some examples of OTPs are Buffy and Angel from Buffy the Vampire Slayer, Scott Summers and Jean Grey (or Emma Frost) from The X-Men.
An OT3 is just like an OTP, but instead of two just two characters being in a relationship, you’re indicating that you think three characters should be in a relationship together. (This concept might seem a little strange, but it is not the strangest thing you could come across in a fandom.) My particular “OT3” for the Girl Genius web comic is Gilgamesh, Agatha and Tarvek. I was extremely excited at the idea that this triad might become canon, mostly because it was pretty clear that Agatha was not really going to be able to choose between them.
Tarvek has proven to be extremely loyal to Agatha, though his interest may be mostly political. Tarvek would be a good but very dangerous political match because of the prophecy concerning a Heterodyne girl marrying an heir of the Storm King. Gil’s interest in Agatha seems to be mostly romantic and he would also be a good political match since he’s Klaus Wulfenbach’s heir. This is also a dangerous political match, but not as dangerous as the one with Tarvek might be. Then you have the growing hints of friendship and friendly rivalry between Tarvek and Gil, and the synergy the three of them have as a team.
Unfortunately, the most recent plot twists have put my OT3 in jeopardy.
Tarvek is currently presumed dead, though he might not be, due to mad science. (Because there really wasn’t much of a “thump” of finality to Tarvek getting stabbed, and we didn’t see a body I am hoping Tarvek returns.) Gil is alive, but currently completely out of his mind due to his father having apparently put a copy of his mind in Gil’s head. (This is various shades of horrifying.) Agatha is currently running around like a chicken with its head cut off and hasn’t had a lot of time to process Tarvek’s possible death or Gil’s current not very rational behavior.
Girl Genius is currently in the middle of a hiatus, and we won’t get answers for the various mysterious of the current plot arc until March. Hopefully we’ll get some kind of closure on the Tarvek situation, and Agatha finally discovers what’s going on with Gil.