I'd replace scarabs with towers. Having more towers will speed up your ability to play pharaohs and nymphs, and thus speed up your damage potential. Also golden nymphs are quite useful in case of a bad starting hand (no pharaohs) so you should be able to survive at least some of bad starts.
If you really, I mean really really do not want a gravity mark, then I guess you are trying to make it a simple rush deck... so it does need moar time pillars or else you will be easily outrushed.
Anyway, by choosing a
mark you leave this deck with no control whatsoever, no defenses, no healing. Any damage blocking shield will leave only nymphs doing any harm, gravity shield will block you completely. Adding
mark will at least give you some (great) way to reduce damage you take so I don't really see much advantage in keeping
mark.
Anyway I like your attempt at a "Revenge of the scarabs!" because I like scarabs (they are soooo awesome!)... but their revenge is not very vengeful without
, being able to eat your opponents alive, that's what vengeance is about!
EDIT:
After some testing in the trainer on AI3 this is a variant that seems the most effective:
5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rs 5rs 5rs 5rs 5s4 5s4 5s4
Strategy:
1. Produce scarabs whenever you can.
2. Play pharaohs whenever you can.
3. If you have any quanta left, play nymphs.
4. If you still have some quanta left, use nymphs ability.
5. Eat anything you can
Basically, card drawing advantage is useless if you don't have the quanta to use it so it has the smallest priority here. The most important is to fill your field with scarabs so that they can eat even bigger threats.
This variant seems to win against most AI3, except gravity (gravity shield). It can probably survive most other cases, even quantum denial (discord, earthquakes) due to the massive amount of pillars (but they are really needed, the deck is so quanta heavy!)
So far I have never decked out, but adding an eternity might help, at least against decks without permanent destruction. Still it works perfectly without one.