Thanks for all the input and comments.
As of this moment, I can't see dedicating specific new cards to "hero control", so as of right now, if a hero is in protection, he can't be harmed. If deployed, he is treated like any other creature. With this in mind we need to be extra careful to not make the Hero too strong in protection... Perhaps some PC will work on it.
Ok so the Hero if implemented would take up a new special permanent slot. It may or may not be vulnerable to some or all PC.
I would suggest that the Hero start out as a Totem (permanent) and the Totem animates into a Hero (creature). This way the Hero while in the Hero slot is directly counterable with PC (except for Shockwave, Earthquake and Trident).
Ahh an excellent solution there OT! I'll think on this.
Since you like this solution then I will continue to answer the rest of question 1 assuming the Totem/Hero mechanics described above.
1) The hero mechanic:
a] How does it work? (PC?, CC?, HC?, safe?)
b] How does it impact the balance of the card idea?
a] I am assuming that it would act like a regular permanent in a special slot (Totem, Shield, Weapon) with an active ability to animate into a Hero/petrify back into a Totem and a passive ability that changes depending on whether it is a Totem or a Hero. This would leave it vulnerable to the same types of PC as shields.
b] This has a few impacts on balance
i) It is a modular card. This means that it has greater versatility than either form represents. This would call for a cost increase in theoretical balance. Uppercut was making a modular series recently and decided a
+1quanta cost increase was appropriate for a 2 mode card.
ii) It can evade fast CC by remaining a Totem, ignore slow CC by refreshing as a Totem now and again and has a minimum of 1 turn vulnerable to PC.
Evading fast spell or automatic active skill based CC is accounted for in the modular perspective of this card.
Evading fast activated active skill based CC (Devour and Paradox) is worth some cost increase. (~+.5quanta?)
Ignoring slow CC is a big concern but so far that only applies to Plague, Liquid Shadow, Gravity Pull Snipe and Fire Shield. This is definitely worth a cost increase. (~+1quanta?)
1 turn vulnerable to PC is a debuff from the modular perspective. But not a large debuff. (- ~.25-.5 quanta?).
iii) The special slot
Since only 1 Totem can exist at a time it deserves a cost reduction. However since it can easily animate it deserves a smaller universal cost reduction and a small Totem version only cost reduction. (-1quanta and -1quanta).
So in total
Totem Version: +0 from regular theory
Hero Version: +1 from regular theory
So now on to question 2
2) Theme:
What kinds of abilities are appropriate for Totem/Heroes to have?
Does this fit?