cool idea but I think that it would be better to half your current gc level and give you that level dark cross as in
Grand cross=10 : Dark Cross=5
Grand cross=9 : Dark cross = 4
Grand=8 : Dark=4
grand=7 : dark =3
and so on and so forth because level 10 shadow gc is pretty hax
you have to sacrifice some dmg for the change of ele elsewise this is wayyyy too brutal in WoE (example: bathory card is wayyy easier to get then angeling and leveling at angels xD don't even get me started
)
Ice, Honor, Pride, HeRo...