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

to avoid naming each unit using the formula "ashy/fiery + [unit name]", I had to get creative - the Ifrit became the Infernal (but there were other plans for that name), and the upgrades received names derived from the Latin words for ash and fire.

SPELLCASTERS - the first unit casts combat spells: Fireball and Wall; the upgraded version has Meteor Shower and a large mana pool, and the alternate upgrade only has Summon Phantom.
And each of them has Soul Drain.