The song for Ep. 12 was chosen for maximum irony. Listen closely to the lyrics, they're pertinent to the story and especially what Lalita is thinking.
EDIT: Further commentary on the episode: incidentally, Lalita's remark to War is the core of my theory why a greenhorn like Ichigo could put a fight against beings that have practiced combat for ages more than him: in any given situation, there are only limited pieces of knowledge and skill that are actually relevant.
After a point, you don't (and can't) really become "more skilled" - you're just trying to do the same thing over and over again, faster and harder each time.
Now, as my Krav Maga teacher put it, there are three things that matter in martial arts: skill, fitness and willpower. If two equally skilled fighters who are both determined to win clash, the one who is physically strongest will triumph - so on and so forth. (A great enough difference on one are can negate meaning of the other two, but that's another thing.)
Out of these, skill, as in technical ability, is the hardest to achieve as far as I know - see the 10 000 hour rule for details (tl;dr: it takes that long to master any non-trivial skill). Physical power and determination are much more fluid - especially in Bleach. And as we all know, those things Ichigo has in abundance.
And that's why he can win, or fight against likes of Gotei Captains at all. Someone like Aizen might be a veteran of thousand battles and have fought against multitudes of different enemies, but only a tiny fraction of that breadth of ability is actually usable
when fighting a guy with a sword with another sword. Ichigo doesn't need
to know anything close to as much as him - he only needs to be equally skilled in a very small subset of possible maneuvers. That's why he's been able to power through some of the strongest characters in the series while remaining largely ignorant of what Shinigami are supposed to know, or most of the spiritual world, really.
Thanks in advance to anyone bothering to read through this rant.