RTF is a global modification that replaces all towns in the game.

The next unit will be a nag, I've wanted to create it for a long time, but there wasn't a reason, now there is – a foot knight at level 6 will soon get teleportation; the animations are already ready, but I want to make the visuals a bit more fun.

That is, the cultists now have two flying units at once – the fire sprite and the knight with teleportation; this is a great reason to remove that flying, teleporting, but also amphibious abomination called "mermaid."
P.S. The model is by zahar0z.