One neat trick with Ravana is in combination with Haas-Bioroid: Architects of Tomorrow: often, you can opt to (or are forced to) make the subroutines on Ravana non-ETRs, which forces the opponent to pass it if they encounter it on a rez in front of a server. If, for example, your only rezzed bioroid is Ansel 1.0, your opponent must break/click through the Ravana to avoid copying Ansel 1.0's bad subs, and then they still pass it, giving an opportunity to trigger Architects. Early game, rezzing a Ravana and using the Architects trigger to immediately rez an Eli/Bran/Ansel elsewhere can provide pseudo-burst economy. That 4 is the same as a Hedge Fund! Admittedly, it a) has to go towards ICE, b) depends on letting the runner through at least one ICE, and c) prevents any benefit of them face-checking that other ICE -- but those are workable. Most bioroids in startup outside of Tyr aren't especially punishing if the runner has a click or two to spare for bad subs.
Any Haas-Bioroid: Architects of Tomorrow deck in startup is probably running all the bioroids available anyway, but among those, Ravana is the backbone of the deck. Plus, if you aren't clicking through, it's expensive as heck to break. At best, Buzzsaw breaks for a credit and two Leech counters. A Ravana on an otherwise-empty central server shuts down any Leech farming unless the runner has a playset of the things on the field. Great Archives protection, especially, against a Criminal looking for easy targets.