Konami used to be fast nerfing broken skill. But it doesn't happen to Master of Destiny and Light & Dark. The reason is obvious, because those skills support archetype from EX Structure Deck
But Master of Destiny could really get an additional "requires X or more Arcana Force monsters with different names in your deck" restriction as a nerf.
The skill Light and Dark should also be available to other characters such as Bastion, Yugi, other characters that would fit the theme. What if they added a Water and Fire type of skill for Bastion?