Vamadeva has three limitations:

• It can only break 's on ICE with exactly 1 .
• It's an AI breaker and hence struggles against the terrible triad
• It costs 6 to install.

Out of these three limitations the only problem is its installation cost.

By it's very nature it is not going to be a solo breaker like Eater or Faust (which also have problems against the terrible triad). Vamadeva is the final piece that rounds out other breaker suites. I've covered it's uses as part of the Deva suite in my Endless Hunger review but here I want to focus on Vamadeva by itself.

Vamadeva is very strong against Rush decks (except possibly which contains Spiderweb and Hive). Enigma is probably the most common problem Vamadeva may encounter that can't be solved without an appropriate breaker. Bioroid ICE can be dealt with using e3 implants and a .

Vamadeva is the perfect companion to Sunny's cloud suite breakers (GS Striker M1, GS Shrike M2 and GS Sherman M3). All of them are quite efficient to pump against large ICE and are highly efficient against multi ICE. However they have a serious efficiency problem against cheap single ICE. Having to pay 4 to break Wall of Static or 2 for Quandary is rather unpleasant and will quickly deplete a runner's credit pool. Vamadeva has the efficiency of Corroder or Eater and is perfect for handling the cheap stuff.

Combined with Grappling Hook + e3 Feedback Implants (to break multi ICE) it is also a great utility breaker for Geist, getting you through the cheap ETR barriers and code gates and saving your Crowbars, Shivs and Spikes for better targets.

Edited to remove misread. I was thinking it worked on ice of one subtype. Obviously that's not the case.

Alright, take 2, this time looking for one sub, not one subtype.

Archangel

Ashigaru (only if there is just one card in HQ)

Asteroid Belt

Bailiff

Bandwidth

Bastion

Brainstorm (only if there is just one card in grip)

Bullfrog

Burke Bugs

Cell Portal

Changeling

Checkpoint

Chimera

Chum

Clairvoyant Monitor

Cortex Lock

Crick

Data Hound

Data Mine

Data Raven

Draco

Excalibur

Firewall

Flare

Galahad (only if the corp doesn't reveal any other grail ice)

Gemini

Grim

Guard

Gutenberg

Gyri Labyrinth

Himitsu Bako

Hive (Only if they have scored 4 agenda points)

Howler

Hunter

Ice Wall

Information Overload (only if the runner has 1 tag)

IQ

Ireress (Only if the corp has just one bad pub)

It's a trap!

Kitsune

Komainu (Only if the runner has just one card in grip)

Lab Dog

Lancelot (Only if the corp doesn't reveal any other grail ice)

Lockdown

Lotus Field

Lycan

Magnet

Marker

Matrix Analyzer

Merlin (Only if the corp doesn't reveal any other grail ice)

Meru Mati

Minelayer

Mother Goddess

Nebula

Neural Katana

News Hound (Only if there is no current in play)

NEXT Bronze

NEXT Silver (Only if it is the only NEXT ice rezzed)

Paper Wall

Pop-up Window

Quandary

Quicksand

Rainbow

Resistor

RSVP

Sagittarius

Salvage (Only if the corp has advanced it once)

Sensei

Snoop

Snowflake

Special Offer

Susanoo-no-Mikoto

Swarm (Only if the corp has advanced it once)

Taurus

TL;DR

TMI

Tollbooth

Tour Guide (Only if one asset is rezzed)

Turnpike

Tyrant (Only if the corp has advanced it once)

Universal Connectivity Fee

Vanilla

Virgo

Waiver

Wall of Static

Whirlpool

Woodcutter (Only if the corp has advanced it once)

Wormhole

Wraparound

Vamadeva is the opposite of solo breakers like Eater and Faust. It is an excellent fourth breaker for any deck that already has strong solutions for barriers, code gates, and sentries. It breaks every trap and every mythic ice in the game, so with a full standard suite you can literally break anything. As an added bonus, it is more efficient than Mongoose or Shrike against many common sentry ice (Cortex Lock, Data Raven, Gutenberg, Guard, Hunter, Rainbow), and superior to Zu13 or Striker for almost every 1-subroutine code gate with strength 2 or higher.

You might not install this deva in every game, but if your opponent is using trap or mythic ice, it is your one-card solution that isn't fiddly like Atman, Brahman, or Crypsis, and its efficiency against sentries and code gates can allow you to recoup its high install cost over the course of several runs.

Surprisingly there is a lot of ice with one sub. I've counted 90 ice with 1 sub, 91 ice with multiple subs, 12 ice with a variable number of subs and 1 ice without any subs (Troll). That means Vamadeva can break 46% of all ice. Assuming the average division of ice is something like 33% barrier, 33% sentry, 33% code gate, 1% trap / other special that means Vamadeva breaks 13% more ice than a regular breaker.

Here's the thing though: because there's no ice breaker that only works on ice with more than one sub you cannot cover all the ice without either a less efficient AI or a conventional set of breakers. And while the break/pump stats on Vamadeva are the same as on Corroder that means it's not the most efficient at breaking barriers (Paperclip). Similarly it's not the best at code gates either due to Gordian Blade being more efficient if there are multiple code gates.

So what you end up with is an AI that sucks at the things AI's are supposed to be good at: working on significantly more cards than normal breakers. Vamadeva is efficient (1/1/2 break/pump/strength) but not top efficient.

Another criminal AI, Mammon, has no restrictions on what it can be used on and isn't much less efficient (2 to pump means it's 1 less efficient on half the ice).

I don't think this is a card that would be useful in practice. Though looking at knowthemeta it's in 5% of the decks, so maybe I'm wrong.