User blog comment:B214/Volume 22 spoilers/@comment-28087053-20170114184806/@comment-9595671-20170125064016

@兵藤 一誠: I've heard the problem was Shiva could have killed Trihexa, but in doing so the cost would be too high. Considering Shiva's a God of Destruction... something tells me that cost is the world suffering the destruction Trihexa would have caused anyways.

@Crimson: Plus the three strongest Evil Dragons were mentioned to be at Heavenly Dragon level in just power, but we've clearly seen Ddraig and Albion were called such for many more reasons and powers they all lack.