The biggest knock against Unsettled Mariner is the fact that it is likely difficult to find room for multiple copies, but the ability to protect your creatures (and yourself) from spells your opponents cast is potentially quite valuable
P/T Set Number 220 Language Espaol Legal Formats Alchemy, Brawl, Commander, Competitive Brawl, Historic, Legacy, Modern, Pioneer, Standard, Timeless, Vintage Rulings (10/2/2025) Azula's ability and the copy it creates both resolve before the spell that caused the ability to trigger
Im actually surprised that I dont see this card more often in Commander because its equal parts efficient and effective
Even in a casual environment where playing an optimal deck might not be your top priority, losing because of flood/screw or bad mulligans isn't fun
You can pass and hold this red instant up, sinking mana into it for a massive burst of card draw before you begin the turn you want to win