1st) Seraph is slightly broken and not very good for comparison, but I will compare it anyway.
I do not agree Seraph is broken. 10|1 stats warrants 9 
, and the ability with an off quanta upkeep is not worth more than 1
2nd) Seraph is a single creature/ divine shield protects a single creature. Antaeus protects all your burrowed creatures.
True, which means that this will only start being more efficient if you have lots of creatures. Fielding lots of graboids/shriekers is quite costly sometimes, and this encourages antlion use
3rd) Seraph has 1 hp; it can be killed by everything at the very first turn, even by a single thunderstorm. Shriekers & Elite Shriekers are beasts with 8|4 & 10|5 stats respectively. In other words, hard to kill in the very first turn.
Shrieker has 3|4 hp actually, but there is not too large of a difference between them. As long as Seraph survives the first turn it's invincible; how many people pack thunderstorms? The only card I can say in the meta that affects seraph more than it does shrieker is firewall. Otherwise, any CC card that is used a lot can kill shrieker as well. (Lightning is the most used, with rage pot, fire bolt, and shockwave next). Unless a creature has more than 5hp, I would not call it sturdy, since creatures from [1-5]hp fall within the same bracket of being easily kill-able.
4th) Divine shield has an off-element cost. Antaeus has an in-element cost.
In my calculations, both are worth +1 card, but yes, you are correct in saying that they are not exactly equal. The cost of an off element upkeep is more than the cost of an in element upkeep. I do not see it as being more than 1 though.
5th) Unupped Shireker has a sweet Adrenaline spot of 8. Furthermore, 
/ 
has lots of synergies and Momentum + Shrieker + Antaeus makes an unstoppable immortal beast.
That is already a 3 card combo, and seemingly very impractical. 4 cards + 12 + 4 
+ 1 turn for an invincible 15 atk creature is not OP. A 15 invincible attack creature should cost around 23-24 . 4 cards + 12 + 4 + 1 turn ~= 25+
6th) 3 or more Shriekers are not than difficult to come by. Remember, you can have up to 12 Shriekers within a deck (6 in Graboid form and 6 in Shrieker form).
Very true, but having one of these on the field slows down your production dramatically. It'll cause you to have 1-2 less than if you didn't have it, and ever single creature you own unburrowed with this is bad for you because of inefficiency.
7th) I repeat, this won't buff Antlions. It will buff Shriekers and, honestly, Shriekers/Graboids are the last creatures that need a buff in EtG!
Graboid/Shrieker can be nerfed. This will make decks based on antlions like fractal antlions much more powerful since this is a card that encourages number
nough said... I don't think I need to explain myself better than this, so I will just ignore this topic in the future. Sorry for that, Furball...
I do not know how to respond to such a comment, but whatever floats your boat.
I noticed I forgot to factor the
upkeep in my earlier calculations. This is 2 cards + 3
for immortality for all burrowed creatures.
2 cards + 3
~= 5
.
Seraph is 9X
+ 2X cards for immortal 9 (10) hitter. 13X
+ 1 turn for immortal 10 (12) X damage per turn.
This and shriekers is 8X
+ X cards + 1
+ 2 cards + 3
+ 1 turn for immortal 8 (10) hitter. 10X + 8
+ 1 turn for immortal 8 (10) hitter.
Looking at it this way, the relative price would be around the same if you have 3 attackers, and you'd only get quanta advantage if you had 4 or more shriekers, but even then, seraphs do more damage than shriekers do.
A Shrieker can also be seen as 1 card + 3
+ 1
+ 1 turn, but that means you'll need two whole turns before you can get the "combo" ready, a bit long to be too practical.
Eclipse is 1 card + 4
for +2X damage.
This is 2 cards + 2
+ 1 turn + X
for +4 (5) X damage, and that's if, and only if, you're using shriekers.
Nightfall/eclipse is much more flexible since it can be used alongside devourers for denial, and vampires for extra healing.
