MArcomage

In my oppinion, this card is a costless game ender, since it can be played with over 40 tower for zero cost and the penalty wont hurt anybody if you win with this card the game.

I would recommend to add at least an extra condition like: "If Tower < 15" or i would make it that it sets the Tower to a specific high.

Well, there is some cards like this one. Redesign, for example.
But I can set some cost for it, like 10-15b.

Redesign is more conditional than this card, i mean, you need at first enough wall for a direct win. But the way it is now, it could help. (Now you can't also summon it with Halfling Thief)

I think it needs a condition, still. The 60 tower for 15 brick is too much, it is an instant contruction win from 40/90 tower and works too well as a finisher.

You could add the If tower < X, or set to a specific height, those both seem fine, or you can try something like (Max Tower - Tower)/2.

Now it costs 25 bricks and gives 50 tower/90 wall.
Come on, Citadel of Myr is instawin from 50/75 tower, and Redesign - from 100/150 total castle. Yes, Citadel is more expensive but it doesn't have any conditions or penalties, and Redesign is now on par with cost, effect and penalty of this one, I guess.

I changed this card.
100 wall instead of 90.
Stock := 0 instead of gems and recruits x0.5.
Facilities -1 instead of -2.

I think the problem is not the wall, it's the tower gain.
With 25 bricks you have a card that can finish the game in a quick tower victory. If you lower that, to 30 maybe, it'd be balanced in my oppinion

Okay, now its cost is 30, tower gain is 35 and no facilities reduction.

Tower: +35
Wall: +100
Stock := 0

I think this looks very much better. I like the concept from the start, but there was to much potential to "misuse" it and exploit a tower victory. This seems to cancel such options.

Now it looks very good :-)
I like your Helms deep ;-)