Thoughts on the Classes of Magic The Gathering and 5e, Part 1

Not something I originally intended to write but, hey, I was asked by a friend to write some more thoughts on ideas and concepts in relation to D&D 5e and Magic: The Gathering, specifically about "What color of mana would each class be tied to?".

This is both a simple and not-so-simple question, so instead I've decided to turn to the absurdly massive array of 3rd party supplements available to 5e. One important concept in Magic, however, is that generally non-human races are tied to one (maybe two, depending on the plane) color of Mana and this rarely changes. As a result, much of this information assume Human characters, give or take a few gifted individuals who could develop far beyond the capacities and association of their race. Of course, the Magic multiverse is vast and near-infinite so just because a thing isn't the norm doesn't mean it can't exist.

Cleric

Mikaeus the Lunarch, by Steven Belledin

In MTG, the Cleric class is heavily tied to White and Black mana, which may initially appear to be a bit odd until one dig deeper. The idea of Clerics being tied to White or Black mana may very well have root in the idea of Good/Lawful and Evil/Chaotic Clerics of early D&D. Combined with the Cleric's ability to either turn and/or command Undead as well as their ability to Heal and/or Harm and suddenly a lot of this make sense. This further plays into classical fantasy imagery, at least before Magic decided it didn't want to do that for brownie points which tend to depict good-aligned Cleric as tied to positive divine forces while the archetype of evil Clerics are those serving demons, evil gods or dark lords.

In recent years, however, with the popularity of the Theros Gods (of all Colors), the idea of tying the divine to just White or Black has somewhat faded, even if the other colors naturally fit other classes better in most cases. Still, any spellcaster whose magic is at least partially derived from faith and/or an entity which may functionally be akin to a god on any given plane could be considered fitting the Cleric class.

White Cleric Domains

Given that White is one of the two colors associated primarily with the class, it come as no surprise that there are many Cleric Domains which are well suited to the MTG color White. These Clerics tend toward the more iconic aspects of the class, namely healing, support and/or waging a holy war of some kind be it justified or not.

• Life is one of the quintessential Cleric domains, with healing being both iconic to the Cleric class as a whole as well as healers often being of the Cleric class in MTG anyway. This is assumed to be among the 'default' option for White-aligned Clerics across the multiverse and represent the abilities of that color very well.
• Light is an another obvious contender for being a mainline White Cleric domain and part of the common/innate abilities of the mana type. There are multiple MTG spells depicting White magic as being some sort of holy light including the incredibly deadly Wrath of God.
• Order (Guildmaster's Guide to Ravnica/Tasha's Cauldron of stupid ideas Everything) represent Clerics which are more aligned to the Lawful side of White mana than some of its kinder and holier aspects, although this need not be entirely the case. White mana has strong association with order and social cohesion nonetheless, sometimes going quite far.
• Peace (Tasha's Cauldron of Everything) is also within the purview of White, since fundamentally the color is about harmony and lack of conflict. A Cleric of Peace represent the kinder, more merciful side of the color as well as its political side all trying to negate conflict where possible.
• Solidarity (Planeshift Amonkhet) is very much a White cleric domain as it gets, since the deity it is associated with is mono-white. The domain is well suited to the typical holy cleric with a reliable weapon in hand, some armor and a holy symbol going around being a beacon to its fellow soldiers and adventurers.

Black Cleric Domains

The Clerics using Black mana are (or rather, were) the archetypal 'evil priests' of pulp and fantasy, indebted to dark gods, eldritch entities and more of than not to demons. They are very much schemers and minions, those who serve a dark power for an equally dark reward or those who simply serve it out of fear. While one could certainly image a plane where Black mana-aligned Clerics aren't evil, its difficult to imagine one where they aren't simply neutral at best.

• Ambition (Planeshift Amonkhet) is perhaps the least 'completely evil' Domain for a Black Cleric and that isn't saying much. The Black color has always been one to focus on ambition, power and achievement at all cost.
• Abyssal is a domain well suited to demon worshipping and/or summoning Clerics which use Black Mana for their end. Demons are the Iconic Creature of Black mana and so this Domain is well suited to those Cleric who wish to unleash the power of Demons.
• Pestilence and plagues are a recurring theme for Black spells so it come to no surprise that a Domain of Pestilence would befit a vile and cruel Cleric which use Black mana, using its power to spread death and decay all around.
• Famine is the twin brother to Pestilence and unsurprisingly, Black can draw upon it too. In turn, Black instill in those who wield it a sense of hunger for more which they can use to spread death, decay and more.
• The vile concept of the Ur Priest is well suited to a Cleric of Black, especially since few of any of them ever truly display anything resembling faith or any positive qualities. The themes of Black draining and parasitism are well on display in that faux-Domain as well.

Other Colors

Generally speaking, the Cleric class is mostly only found in White and Black. For example, Blue Spellcasters tend to be the intellect-driven Wizards, while Red has the emotion-powered Shaman and Green has the nature-connected Druids. As a result, Clerics of the other three color tend to be a bit more rare. Should they exist, they would likely be tied to Planes which place a strong importance on specific Gods or similar divine entities where an established priesthood could exist.

• Red Clerics would be well-suited to any Domain tied to violence and conflict, such as War as well as any Domain which give Fire or Ice damage spells. White/Red Clerics overlap greatly with the White Clerics but tend to increase the martial bent of White even more.
• Blue Clerics are quite rare and mostly tied to Deities associated with Knowledge. To a lesser extent, any Domain that give Ice or Illusion spells can be tied to blue. White/Blue Clerics tend to increase the traits of orderliness found in White, preferring to combine strict law with logic. 
• Green Clerics are well suited to the Nature Domain or any Domain which ties into natural forces. Anything more would make them overlap far too much with the Druid class, which is very emblematic of Green overall.
• Black/Blue Clerics have a few domains that suit their (admittedly rare) niche, namely the Madness domain. These would be mad hierophants and cultists worshipping mind-breaking horrors.