First impressions, mostly about idea / purpose / comparison of the pieces, not so much cost :
Ares - L magic destroy seems better than straight line (e.g. FE), the piece has huge mobility to apply it, compared to other magic / ranged destroyers. Apart from destroy, the melee attacks are considerable threats too. So even if it has a condition, seems a bit too much / good. Although I like the "kill to enable" idea, the new released Gluttony has it on as long as it lives, so it takes the novelty a bit from it.
Cancer - suitable name. Tiers 2 and 3 are just much better than Phalanx imo. Mobility, not immune to displacement. Armor - having to be destroyed for each square separately makes it much better with each new square of it. While it has the 4 "holes" on lower tiers, that I might live with, the 8 all around just too much imo.
Capricorn - reminds me a bit of Harpy. Too many things going on, messy to calculate anything (maybe just for me), not the kind of piece I like myself (not saying it's bad).
Leo - Better and cheaper than Behemoth, and with morale (and therefore the immunity) buildup on top. I like the synergistic combination of the activity with morale gain, but seems too good, at least for the moveset / numbers.
Libra - at first, I thought the ability is somewhat similar to Temperance's, but not really. Temperance is predictable, and goes from lower target count to higher reliably. This one just swings at any point, it's a much bigger and powerfull, I can't really decide / predict if I'd like it. The idea of the swings I do, but how much it swings power from one player to another, I am a bit affraid. Also, it seems both players would want to have Lich just to swing this one in their favor reliably, and with not completely wasteful abilities / sacrifices.
Pisces - I can't recognise the 2 described ability squares from description on the board moveset. Also, I don't see what is the purpose of the icicles in augment.
Sagittarius - tiers 0 to 2 I like, only range 1 shooting, but better mobility with L attack/jump, nice alternative somewhere between ranger and dryad. Tier 3 is just better than ranger, since you sacrifice only 1 out of 3 forward shooting squares, for still keeping much better mobility. Pricing this could also serve as comparison to how much activated Ares is better / cheaper.
Scorpio - Plus for keeping the triggered poison only on range 1 on higher tiers, otherwise I would object similar way as with Sagittarius tier 3. Trigger on magic with range seems very good, but then it's not as much by being slow / curable poison, and the tempo gain is again balanced out by value loss / capacity of poison casts. Not discussing costs, this one is very nice imo. I also thought about the theme of scorpio, and got some ideas that I might use in suggestion later :) .
Virgo - There is quite recent post by Ryan about base Behemoth (https://steemit.com/hive-135459/@ryancoretotstceo/the-myriad-problems-with-behemoth) where I oppose his opinion that it has very horrific cons, but here I think this does have one :) . What is it ? This just waltzes in to enemy King, needs just 1 defender to retake King, and not a whole army of enemy champions can do anything.
As side note, I don't like that there are many new threads about same things, instead of dedicated forum threads in old way, but such is the way when farming steem creeps in to discussions of free time activity :) .