The Fiend and Scorpion are Great 
With a little effort, many of these units can be combined in part of totally with other Units.
I could see the Fiend using the Black Coffin as an Airdrop for example.
I have already combined the Large Skull with the Reef and sunken ship as a "Devil Reef". The Reef uses rhodie's Maelstrom as the Attack and the Skull is in the Death with the Reef vanishing. I remade the Flcs and sounds along with re-coloring it all specifically for the water in the game.

With a little effort, many of these units can be combined in part of totally with other Units.
I could see the Fiend using the Black Coffin as an Airdrop for example.
I have already combined the Large Skull with the Reef and sunken ship as a "Devil Reef". The Reef uses rhodie's Maelstrom as the Attack and the Skull is in the Death with the Reef vanishing. I remade the Flcs and sounds along with re-coloring it all specifically for the water in the game.