It speaks volumes of how deep the color blue went in Invasion Block given that this card wasn't even in the top three blue cards of the format
Its requirements are steep, but they also create an incentive for players to include blue creatures in their decks
The Soul Stones harness ability is a bit overblown given the massive set-up cost, but it's all gravy on a massive upgrade to Charcoal Diamond, and an indication that the other colors will be getting some improved mana rocks soon enough, probably a few as early as Marvel Super Heroes next year
Nyla, Shirshu Sleuth Saffgor: Flavorful, powerful, but still fair
Magic fans would certainly benefit from adding this versatile card to their decks
Getting two cards out of your library and into your hand will allow you to make sure you are playing lands every turn to get your big green creatures onto the battlefield