Theros Beyond Death introduced Gods and Demi-gods, of all five colours. the ability “devotion” to a certain colour is the number of coloured mana cost to each of your permanents, so if you had a Rambunctious Mutt and a Savai Sabertooth your devotion to white would be 3.
here is a table of the five mono-coloured Gods:
|Heliod, the sun crowned||white||4/5|
|Thassa, deep dwelling||blue||2/5|
|Erebos, Bleak Hearted||black||3/5|
|Purphoros, Bronze Blooded||red||4/5|
there are also other gods in Theros, two of which are in Theros Beyond Death, and others which are in older sets.
Theros is basically the Greek plain of existence. the next post will be on Zendikar Rising, the new set out now!