Cycles

While designing new races for Starcraft on BlizzForums*, I became intimately acquainted with a concept I now know as "cycles", the idea that certain things should exist on all sides in an asymmetric game, in different forms.
*See Beginnings Part 1

In Starcraft, this was a common feature, my favourite example being what I called "Outrangers": units that had a longer range than the game's defensive buildings. Each team had one, they all only targeted ground units, but aside from this they were completely different.
Guardians flew above the battlefield, and blasted individual targets. In keeping with the Zerg insectoid themes, guardians were produced by pupating an earlier Zerg strain.
Siege Tanks pounded whole regions with splash damage, they had the longest range of any unit in the game. Like most of the Terran buildings, they were able to move in one form, but became stationary when using their full abilities.
Reavers also used splash damage, but rather than artillery fire they fired "scarabs", small robots which had to move along the ground to reach their target. They required resources every time they fired, in keeping with the Protoss tendency towards high expense.

From my experience, there are 3 main purposes to cycles:

1. They provide some required function to all sides of the game, without making them too similar.
   The "outrangers" are a good example of this.
2. Cycles make it easier to balance the game:  The similarities between members of a cycle make it easier to compare how powerful they are, and easier to pinpoint what makes their power different.
3. Cycles illustrate the differences between the groups. The similarities make the difference stand out more; for instance the legendary spirit dragon cycle in Magic the Gathering. They all have the same total cost, the same stats, and do something when they die: But each does something that fits within its colour.

With Clash of Blades duel deck format, cycles have to be done a little differently. The easiest way is to do two-card cycles, known as mirrors.

Which brings us to a couple of cards I wanted to show you: