Reanimating dragons.

[Yyrkoon]

I have a problem with the NK reanimating dragons as these 2 forces are set in diametric opposition.  Ice and fire-battling through all time but neither controlling the other.  Yin and yang or what have you-it just seems to upset the balance too much if one can claim dominion over the other.  Is this GRRMs idea as well, or simply a manipulation by the show runners? Who have created problems in the past as they've bent rules which GRRM has been comparatively consistent with creating a malleable rule set down the road.  I for one don't think the NK should be able to manipulate fire, i.e. dragons as they represent the pinnacle of the forces of fire.  Of course there is the obvious theme of life and death, but I disagree this over-rides the magic of ice and fire.