What is the lore behind why soul coins have the symbol of Bhaal on them?

I am struggling to find an image of both sides of a Soul Coin (Baator’s currency), but everywhere I’ve looked, I’ve only found only one side bearing a letter and the other side depicting a skull with blood droplets flying around it.

But it is the symbol of Bhaal. Why does it appear on Baator’s currency?

Am I correct about how soul coins look? What images appear on the sides of a soul coin, and why?