A fundamental relationship in the mathematics of Netrunner is the "rez-to-break" relationship. Simply put, how much does it cost the runner to break a piece of ice once with a decent breaker, compared to the cost the corp pays to rez it?
For the vast majority of ice and breakers, it costs the corp more to rez it than it will cost the runner to break it once. For example: a Wall of Static costs 3 to rez, but only 2 to break with Corroder.
This leads to a dynamic that experienced players are well familiar with. Forcing the corp to rez ice is good for the runner; you are coming out ahead on that interaction. Once a piece of ice is rezzed, though, you don't want to break it any more times than you have to, because it's just a straight loss for you, leading to multi-access, bypass, and ice destruction tactics.
Ankusa flips that script. When Ankusa is your fracter, every barrier must be rezzed every single time that they want to protect their server. More than that, actually: they have to rez it AND reinstall it, costing clicks and probably credits if they had other ice on the server. Bonus points if it had advancement counters on it.
But at the same time, Ankusa's stats are pretty horrible, compared to Corroder. It's going to cost you at least 1 extra (against, say, a Wraparound or a Vanilla), will typically cost you 3 extra (against any single-sub barrier bigger than a Himitsu-Bako), and an Ashigaru just makes you cry. This (along with the 6 install cost) means that you are paying a substantial cost for the benefit of taxing the corp. You can reduce this strain with strength-boosters like Dinosaurus or Net-Ready Eyes, but you can't get around the 2/sub cost with e3 Feedback Implants because you have to break the subs with Ankusa, not with hardware.
So Ankusa puts enormous economic strain on both sides, and the winner of this money-fight will win the game. If the runner has money and the corp doesn't, the runner will just bounce all of the corps barriers, leaving their servers porous. Remember--if you bounce a piece of ice on click 1, that leaves you three clicks to pound that server before the corp can put it back. Medium enjoys that interaction on R&D.
On the other hand, if the runner can't manage to get enough money to push through the barriers in the first place, then the game is lost. And that leads me to the next point--Ankusa is absolutely a big-rig card. You need to have fat stacks to play this card. Fat. Stacks. Magnum Opus is a start. Aesop's Pawnshop builds might generate enough money to fuel this. Whatever it takes.
The other flaw is that Ankusa is only a fracter, not an AI. A Magnet is basically identical to Wall of Static but can't be bounced with Ankusa. You can try to patch this flaw with Paintbrush, of course. But the fact that the ice has to be rezzed means that you have to break it twice: right after they rez it, and again after you've painted it barrier. This halves the efficiency of the bounce, to say nothing of the 2 MU cost of Paintbrush (which gets problematic if you're trying to run it with Magnum Opus as well).
In summary: it's a big-ass breaker that needs a monster economy behind it, but once it gets rolling it can really give a barrier-focused corp hell. With those caveats, I think it falls solidly in the "jank" category, but it is some grade-A jank that's well worth trying out at a casual night.