By locking down the opponent's biggest threats, she protects her allies from being challenged while keeping the paths completely clear to quest for victory without fear of immediate retaliation
With access to blue, this lets you keep up the threat of counterspells, removal, or something nasty with Flash, and if you dont end up needing to use any of that, you get to play this at the end of an opponents turn and untap further ahead in cards and/or mana
Theyre not seen in play outside of limited formats, and on the secondary market only the enchanted rares are often worth enough to make pulling them exciting
However, the biggest problem with the Emerald/Sapphire Azurite Sea deck is that it's a bit unfocused
That just leaves the Imperium factions deck, Forces of the Imperium, which should be out later today, on PleasantKenobi's YouTube channel