In the terms of the evolution of the light in the Destiny universe I think a safe place to look is no farther than the Supers the Guardians use over all. In Destiny there is no better example of the versatility and volatility of the Light.
The Light has proven to be able to do the unthinkable in terms of how mankind assumed the Universe worked until it was discovered with the Traveler’s arrival. It clearly can extend life indefinably if needed and possess the ability to tap into powers beyond that of the natural world that is governed by KNOWN laws of physics.
But if we are speaking strictly in terms of the Guardians and their use and changes to the Lights use we must again look at the Supers.
A lot of this theory is based off Bluecrew86’s theory of how the guardians summon their Light. The summoning rituals change the outcome of the super. Essentially the Guardians evolve the use of their light based on the need of the crisis or situation the City or mankind is facing. Basically, the Supers come and go as they are needed. In saying that, we must look at the situations that the Guardians and mankind have faced since the Collapse to where the City and its Guardians now stand.
If we look back to the Dark Ages and the rise of Iron lords and start of the rise of the City we see the early use of the Light in the formation of the Supers. While it’s unknown which Supers came about first, we can see based off evidence from the Grimoire and limited data we have on the Iron lords, early Guardian Orders and events of Dwindler’s Ridge that all the known Supers, except for the Dawnblade and Sentinel, developed at some point before the events of Destiny 1. According to lore no one knows who the first Arcstrider was. Dawnblade and Sentinel is a perfect example of the Guardians evolving the use of their light to better suit their needs.
If we look at the Stormcaller, Sunbreaker, and Nightstalker, we see that these Supers go in line with the need of the growing early City. The Nightstalkers would track and trap the Fallen in their attacks slowing or stopping attacks long enough to allow other Guardians to gun them down. The Stormcaller was simply a reaction to the overwhelming number of enemies facing the City. As with in game mechanics, Stormcaller is fantastic for attacking multiple enemies at the same time and holding back large groups of enemy forces. Finally, the Sunbreaker’s Super, the Hammer of Sol, is exactly what its name implies – a hammer strike. It is a massive amount of damage in a brief time with lasting effects that not only kill enemies but denies freedom of movement with the use of pools of Light left behind by the exploding light of the Hammer.
When we move to the time of vanilla Destiny 1, the Guardians are set into the Supers they are using. The other Supers have lost their necessity. Which might explain part of why the Sunbreakers left. They didn’t want to change or felt insulted that they were no longer needed as much as the Defenders were. The Stormcallers crowd control was no longer needed as much as the strong devastating blows of a Nova bomb or the support offered by the Sunsingers. And while the Nightstalkers still existed, they were no longer the only scouts on the limited frontier the City was scouting and operating on, therefor their numbers dwindled.
Back to vanilla Destiny. Hunters are working with Gunslinger and Bladedancer. The Bladedancer’s Arc Blade is meant for up-close and personal attacks. Killing the larger enemies of the city before they got near the City. The reach of the hunter here is limited, yet vicious. The Golden Gun much the same. Limited to massive damage quickly but with only three shots it can’t deal damage over a large area to a large group of enemies.
Warlocks are working with Voidwalker and Sunsinger. The Voidwalker is meant for massive damage quickly, with an ability to stop large groups of enemies and/or area denial. The Sunsingers have taken the role of support bolstering their fellow Guardians in the fights and serve as a force multiplier in military terms.
Finally, we have the Titans whom Supers again are limited in their ability to TAKE ground or deal damage to large spread out groups of enemies. The Striker ability is a single, devastating smash – a shock attack, meant to disrupt the enemies’ organization and normal rank and file. The Defender’s super is just that, a wall. It is capable of holding ground, though the taking of new ground is limited unless working in tandem with other Guardians. But the Titans’ duties are mainly to the Walls. At the time that we are speaking of the City is still in a very defensive posture. They are not wanting to spread out and attack because they feel it is too dangerous.
As the events unfold and we move to the time of the Taken King the City has started to grow again. Humanity is growing in confidence that they can expand beyond the limits of their own walls. With the decimation of the Fallen and Hive forces on Earth and the Moon through the death of the Crota and thwarting of Skolas and his uprising, the City is now on the attack, growing and expanding. They are pushing out. While we are at war the Cabal at this point it is limited to strikes and raids against Cabal command that is limited to the battlefields of Mars and not all out total war. With the arrival of Oryx’s hordes of Taken and enemies across the system engaging in war against each other, a new yet tentative alliance with the forces of the Reef is formed by the City’s governing powers, who realize they have a new chance and want to expand to new horizons.
With the increase of enemies, the older subclasses start to make a comeback. Stormcaller, Nightstalker, and Sunbreakers become relevant with their need not just in terms of game mechanics, but lore-wise as well. The City needs these old powers of the Guardians to bolster and fight the new threats. The Stormcallers and Sunbreakers can cull large groups of enemies in the name of defense of the City while the Nightstalkers spread out and start scouting long forgotten areas of the solar system. The Taken War and the all-out attack of the Guardians require every power the Guardians had their disposal.
The SIVA crisis did not generate the need for new Supers I believe because the crisis was not on the scale of say Crota, Oryx, or the Vex. The Fallen threat was limited mainly to the Plaguelands and while defiantly a danger, not one that threatened humanity’s interests across the system.
Now we move to the time leading into the Red War with the Cabal invasion. Guardians and the City are the major powers within the system. Most of the major threats, as Cayde says, the “Guardians have handled.” Humanity is now on track to retake its home. Confidence is high and the City can spare defense because the threat is not clawing at the walls every hour of every day. The Cities militia and static Titan orders can hold the city while most Guardians do battle with what threats still remain. This is where we see the evolution of the supers.
First, we have Titans. The Striker moves from a single devastation blow to a multiple striking sprinting juggernaut capable of taking on large groups of spread out enemies. The Defender becomes the Sentinel, which while still possessing the ability to defend ground, sees the ability via their Shield for that wall to move forward and not be a static defense. The Shield can also be used offensively, giving its wielder the ability to smash into foes that are close or even being thrown across a distance. While they lose some of their defensive capabilities, the Sentinel gains rather aggressive ones. The Sunbreakers remain largely unchanged due to their ability being an already aggressive Super to begin with.
Next we have the Warlock. The Sunsinger is the greatest example of change for this class, having evolved from being a support class to be an all-out aggressive flying daemon of hellfire, joining the other Guardians in this all-out offensive approach. The Voidwalkers have mastered their Nova bomb to a point where it aggressively tracks enemies and causes even greater damage. The Stormcaller remains largely unchanged, except for an increase in the Warlocks’ power – a mastering of the skills, evidenced by the Arc soul ability.
Finally, Hunters. The Arcstrider is the best example of a Light evolution in this class. The short Arc Blade has become an Arc Staff, which when combined with the class’s increased acrobatic ability greatly increases the Hunter’s deadly reach. The Gunslinger has evolved to have more shots, which while less damaging per shot, can now gun down more enemies – though they still retain the ability to perform overwhelming damage with a three-shot variant of the Super. Similar to the Sunbreaker and Stormcaller, Nightstalkers have mastered their craft and remain much the same.
With the events of the Red War still fresh in humanity’s mind and the awakening of the Traveler we are likely to see the continued evolution of Supers and the Guardians use of Light. Humanity stumbled, but they are once again on the attack. With Ghaul ‘dead’, the Cabal emperor playing some sort of proxy game with us as well as seeing us as ‘members’ of his empire and possibly somewhat at ‘allies’, humanity expanding and discovering dormant Golden Age tech, and the newly awakened Traveler’s power grow and stabilize, I’m sure we will see the continued evolution of the Guardians use of Light.