MArcomage

This card exists for almost a year, and now I can say - and I guess many would agree with me - that it's not good at all. This card sucks in almost every way you can imagine. It's not so good in tower+ decks, because it costs 20B, can be played only once per game (okay, twice if you're not lucky). It would be somewhat useful in old Holy/Soldier decks based on Zealot, but we don't have it anymore. Soldier decks can use it to raise Soldier tokens, but 20B could be spent for Desert outpost, Troll bridge et cetera. Holy... Well, there are much more effective ways to raise tower in Holy decks.

Remake it, please. And there is a couple of suggestions from me:
1) 18B cost, Tower: +30-2N, N = Tower/Max tower * 10.
2) Cost and effect are the same, but add "Dungeon: +1, won't raise Dungeon above 6".

I agree and I like the second suggestion.

The dungeon+ idea is nice.
we can also rise the limitation on tower: can't rire tower above 2/3 of max tower (or 3/4?)

As much as I like this playing this card, I would have to say it is severely OP in many decks , especially in the short mode. At the cost of 20 res, it gives you both the effects of, say, blacksmith (10 res) and 1,5 x effect of the ivory tower (16 res). Yes, its cap to both dungeon and tower leaves it slightly useless towards the later stages in the game, but now it has the power of a game changer in rush destruction, brigand and, maybe, some other decks by giving both additional recruits production and a gigantic tower boost. I would suggest lowering the tower gain to 15 to make the effects more consistent with other bricks-only cards, e.g. desert outpost.

Yes, Templar castle does what you described in exact terms - and I have to say, just after recent consideration the price tag for what the card does is excellent. Tower cards tend to be good in any deck - the only limitation on them is your Bricks budget. Templar castle is a refreshment of an exception where only rush decks who are otherwise tower-starved put them in the deck. There is no particular difference in comparison to, say, Dwarven wall put into a resource deck or Working together in a slow-paced deck. The fact you have to work around them for their full value is what makes them good in practice.

Mojko already considers a minor nerf of the Dungeon gain as part of the summer update. Perhaps wait and see the result? You might be satisfied with less.