Its not an adventure spell, but Uro is fantastic when your strategy is self-mill
Making 1/1 lifelinkers is a reasonable trade for the lower starting loyalty as you grow your life total and Sorins loyalty simultaneously, even if all you are doing is chump blocking every turn
One of the best perks of Decidueye is that not only does it have a hefty amount of health, but it also can do a moderate amount of damage per turn
By the way, BGU mana cost is also quite fitting (at least for me), possibly representing Sin's connections to oceans (blue), death (black), and the natural cycle it's strangely bound to (green)
Properly outfitted, drakes made perfect sentries for vedalken strongholds
Emerald Lorcana cards tend to prioritise defence and effects over strength, which you could choose to balance by combining it with a more challenge-focused colour such as ruby or support with the protective powers of amber or amethyst