Sure it is, she can deal at least 2 damage to herself every turn for as long as you keep the game going.
Fixed Point stays around for just one round, and she doesn't have a way to deal herself damage to deal out damage and rinse and repeat as long as she wants. She could be knocked down to below 0 and do massive damage with Wrathful Retribution, but it won't be on the scale of Absolute Zero's doing. As his is truely infinite.
And yes Haka's battle do stack, though if you discard 37 cards and save one Haka of Battle, then used that on the next turn it discarding 3 cards (1 from the draw phase of the previous turn and 2 from haka of battle) it would yield to 3 additional points of damage, considering the size of attack as it already is, i'm not so sure 3 more damage would really do much, as Akash'Bhuta would be the only one that could of survive it.
Here's my idea for max damage (discounting the fun infinities from Fixed Point):
- Haka of Battle, discarding Haka's deck.
- Rampage, hitting Akash'Bhuta with the first big hit and all of her Limbs (which have been kindly reduced to low hp for you) with the smaller hits.
- The Limbs are destroyed, causing A'B to hit herself for a bunch of damage, and stored under Savage Mana.
- Power for Savage Mana, dealing a nice big chunk of damage itself and destroying the Limbs again!
Haka's discard has to be from hand. Other than that, very shiny! 
I think he may have been refering to the fact that he has the entire deck in his hand. Other than the other cards needed to do this.
He could also be refering to Haka of Battle stating it is Haka's next attack. Nothing is stopping you from discarding your entire deck, shuffle for re-draw and later discarding your whole deck. Eventually you run out of health and go incapacitated, but you can string a couple of them together for one massive damage boost.
I was referring to having the remainder of Haka's deck in hand, but I suppose that both interpretations are correct.
Wasn't there also the Distortion card from realm of distortion that turns all non-target cards into targets. So you can use rampage to also eat all your allies' card for more power to Salvage Mana.
Imbued Vitality. I think that was already mentioned earlier in the thread :).
So to recap, we now have two methods so far of dealing theoretically infinite damage -
1. Absolute Zero with Isothermic Transducer, Imbued Fire or Twist the Ether, and Fixed Point.
2. Haka, with Hakas of Battle and a whole lot of time.
Any more?
If you've got a loooot of time, then at least one incapacitated hero can give a +2 to any hero's next damage dealt each turn. Or, Chrono-Ranger and Expatriette can stack an infinite number of 1-damage projectile attacks on a power, which is somewhat stymied by damage resistance but can be used to murder every goddamn thing you want dead.
I think Chrono-Ranger's incap is an immediate effect, so it won't actually stack.
Whoops, you're right. Expatriette's still works though!
Though realistically only Abzeros is true Infinite damage. infinite damage combos have to be done all at once, in one round to really /count/
*snicker*
the absolute max damage you could do (besides AZ) is 154 damage to all non-hero targets with Omnitron-X, using only one power.
How? Do tell :D
It involves Fixed Point, Tendrils of madness (wrested to hit Omnitron), Plague Rat's advanced rules, Plague Locus, Legacy (with Inspiring presence), Argent Adept (Syncopated Onslaught x2, and an extra galvanize), Visionary (both twist the ether), Unity (2 hasty augmentations; one on Argent, doubling his contribution, and one on Omnitron, and a swift bot), all 3 platings, and defensive blast.
Basically, use fixed point to have all 3 platings out, and have the tendrils hit Omnitronks. Then Legacy galvanizes and inspires, Argent uses Syncopated onslaught twice and Supertonic once for a bonus galvanize. THEN Unity plays hasty augmentation on Argent (for 2 more onslaughts and a galvanizing supertonic) and one more on Omnitron for a +2 boosted Defensive blast, with all 3 platings. This causes him to do one point of damage of each damage type -- boosted by 13 each -- for a total of 14 points of each type to all non-hero targets.
Granted, there's a LOT of setup involved, but it's the absolute max that I could come up with.
Bonus points for going against Akash'Bhuta. You lose the +2 from Plague Rat, but giving Argent's +4 from the onslaughts to AB makes her suicide that much faster.
That'sā¦ beautiful. I think I can build on it though 
So we have 1 + 1 (TC) + 2 (PR) + 2 (Leg) + 3 (AA) + 2 (Vis) + 5 (Uni) = 16. (Huh. You did better than you thought :P) But a Polyphoric Flare or even a Silver Shadow can get you +4 on AA's go, so you get 17 per attack, or 187 total 
Please explain how you are using Polyphoric Flare to get an additional point on AA's turn, as this is the second time you have mentioned it, and all Instruments and Vocalize are already covered on Argent's power phase.