Total Recommendations: 2
As noted by others, there are many similarities, and if you liked one, you'll almost certainly like the other. Both take place in a dark fantasy world and medieval setting. Both focus on a character who lost someone dear to them and is on a journey to find the killer, a being with awesome power evolved beyond the main character's current ability to defeat. Death, fighting, and monstrous powers and beings abound.
Although the trappings are very different (including the medium: playing igo in one, acting in the other), both series focus on the rivalry between a person who is practically royalty within the medium (with a famous parent, wealth, and public expectation of success) and another who stumbles onto the medium with no prior experience, but who finds a remarkable talent and passion for it. Both seek to master the skill enough to attain an ultimate goal (the hand of god for hikago, the lead in a legendary role for glass mask). And in both, the established character finds new drive when they realize the talent of the other and recognizes them as their lifelong rival.