TL;DR - With the preview of the Void 3.0 changes, I wanted to take this opportunity to speculate on and discuss what abilities Bungie will turn into Keywords for Arc 3.0 and Solar 3.0 reworks.

What do we know about Void?

To paraphrase parts of the TWAB, Bungie will be applying the same methodology that approached Stasis with, making certain effects into mechanics shared between the subclasses of the same element. This is to give a each element it's own "feel" and specialty while allowing other game components to tap into that shared language. To help figure out what Arc and Solar might look like, let's analyze the Void keywords.

Bungie took existing effects from all three subclasses and made them into keyword "verbs".

Negative Void Effects: Suppress // Weaken // Volatile

Positive Void Effects: Void Overshield // Invisibility // Devour

Overall, Void Light seems to have a very defensive and controlling theme to its abilities.

Suppression is an effect that is pretty synonymous with the Void. Suppression has been in the game from the beginning with Suppressor Grenade and grew into Shadow Shot, Shield Bash and a few other perks like the reworked Bombardiers. This shuts down abilities and stops AI enemies from shooting.

Weaken may have started with the Sunbreaker's Melting Point (which exists in the form of Hammer Strike on top tree Sunbreaker at the moment) but due to the nature of Shadow Shot, the inclusion of Shattering Strike on Wraith Nightstalker, and the Oppressive Darkness seasonal mod, it appears like Bungie is tightening Void's grip on this damage boosting debuff. Weaken will now slow in addition to increasing damage dealt to the target, while AI enemies lose fire rate and accuracy.

Volatile is a new term for an existing effect. This is a the Commander Sentinel's Void Detonator turned into a core mechanic of Void Light. This stands out from the other Void effects for being much more offensive in nature.

For the Void buffs, it appears they've taken the iconic effects from each Void subclass an made it a keyword feature of the Void element. Void Overshield from Sentinel's Defensive Strike. Nightstalker's various ways to become invisible. And the Devour effect from the Attunement of Hunger Voidwalker. Most likely, these effects will remain centered in their class of origin, but will on occasion be opened up to the other two classes to varying extent much in the same way Revenants, Shadebinders, and Behemoths are focused on Stasis Slow, Freeze, and Shatter respectively.

I presume that this is going to be the benchmark for the other two elements. Three negative effects and tree positive effects, all pulled from existing abilities. Slight tweaks to balance them and make them operate in a broader framework are to be expected.

Arc Keyword Predictions

Negative: Blind // Arc Chain // Electrify

Positive: Pulsewave // Resistance // Amplify

Blind: I'm pretty confident that Blind will probably make up one of the Arc Debuffs. Blind has been an effect on Flashbang Grenades since D1, and it exists on both the Current Arcstrider (Ebb & Flow) and Wind Arcstrider (Disorienting Blow). And most recently, they put it on the buffed Bombardiers as the Arc effect. So I suspect they might change the names of these existing effect to be "Blind". My only worry is that Arc Blind would be too similar to Void Suppression in PvE, so I hope something gets added or adjusted to make it more distinct.

Arc Chains: This is less a status effect and more an... elemental effect. Stormcallers would most likely still maintain a focus on this effect, but it seems like a very natural choice to include in the offensive Arc effects and it would be a very evocative tool for the other Arc subclasses to have. I believe they will most likely call it Arc Chain to make it synonymous with the Arc Web effect with Exotics, weapon perks, and armor mods could then make use of this now keyword ability. Although that would really power up Arc Web, so I suspect some balancing will occur with that, so Riskrunner doesn't become the ultimate battery for the Stormcaller.

Electrify: I feel pretty confident in saying that middle tree Arcstrider's Electrify effect is the most obvious choice for an Arc "Verb". At present, triggering Electrify process will cause the target to become disoriented and grants you ability energy for doing so. I think it makes sense to have it fill a similar "priming" role that the Stasis Freeze or Void Volatile effects perform for their respective elements. I think the two most likely outcomes for detonating this either the blind effect or launching Arc Chains. In either case, the other effect could make an appearance as an Aspect or Fragment.

Pulsewave: I'd say pulsewave is probably the weakest link in the Stormcaller trees, while it is far from a "bad" effect I would not say it is particularly resonant ability compared to the likes of Arc Web or Arc Soul. Looking at the effects Arcstriders and Strikers have, movement appears to be a subtheme of the Arc element. This is further exemplified by the recent sprint speed buff added to Electrostatic Surge. Turning Pulsewave into a universal Arc effect would further cement this specialization.

Resistance: To give the Arc subclasses their own defensive mechanic, I believe Bungie may give them keyworded access to the "Resist" effect. While Void also has a few Resist effects in the Protective Light mod and Omnioculus exotic, Void is already getting Overshields (and Devour for healing), I think it makes sense to expand things past the Wind Arcstrider's Lightning Reflexes.

Amplify: The Arc element has quite a number of CQC related effects. From the Combat Style mods alone, we have Reactive Pulse, Lucent Blade, Striking Light, Heavy Handed, Strength of Rasputin, Well of Ions, and Overcharge Wellmaker. Therefore, I think there is a strong chance that Bungie will codify the melee damage boosts that the Arcstrider, Striker, and aforementioned Well of Ions share. Due to melee combat being less than desirable in higher end content, I hope that an effect like this would be buffed from the current levels of Combination Blow and Knockout, despite already having been buffed during Arc Week

Solar Keyword Predictions

Negative: Burn // Detonate // Sunspot

Positive: Heal // Empower // Temper

Burn: This damage over time effect is pretty much a given for a Solar debuff. It's been in the game since D1 and is on all three Solar Subclasses. It's an offensive damage over time effect and it can be used to convey other effects. I feel like Gunslingers are most likely to take up the burning niche with their Knife Trick and Incendiary Grenade.

Detonate: Looking at the other elements, I think we are indeed moving towards effects that prime a target with one effect and reward you with another. For Solar, we actually have a few cases of this already: the Sunshot and Ticuu's Divination exotics, and the reworked Igniting Touch. Solar just has a general explosion focus as demonstrated by the Solar Warmind Cell mods, Elemental Well mods, Explosive Pyre, the "Combustion" explosion on Celestial Nighthawk, Celestial Fire, etc. The Igniting Touch rework (and Celestial Fire to a lesser extent) makes me think Warlocks are the most likely class to take up this keyword as a specialization.

[Edit] Highlight/Illuminate: Having talked to u/VDRawr in the comments, I think leaning into the Sunshot's highlight effect might be a better an alternative to Detonate. On it's own it doesn't really do much, but I think it would be a good vehicle for other effects. I'm thinking that it would serve as the "primer" for Solar with a burn being the reward for "detonating" it rather than the other way around presented above. While this would still have similarities to the other "priming" effects, Freeze, Volatile, and the reworked Electrify which I theorize about. I think having the burn come from triggering this effect would feel distinct. Maybe less upfront damage, but you get the burn and burn synergies. I'm still not sure whether Hunters or Warlocks pick up this Highlight/Illuminate effect. My gut says Hunters would make the most sense with Warlocks focusing on the burns, but I think Hunters currently have more support for burn builds.

Sunspot: Since Weaken appears to be leaning more in the direction of the Void, Sunspots are the only remaining choice that that makes sense to me. Sunbreakers would obviously still maintain their focus on the effect, but it would become available through other forms, like weapons and armor.

Heal: I think healing is the most obvious route to go with to fill the defensive buff role for Solar. Both the Solar Warlock and Solar Titan have built in healing effects: Sol Invictus, Divine Protection, Phoenix Dive (and Rift). Not only that, but we have seen other healing effects associated with Solar such as the Heal Thyself and Kindling the Flame CWL mods, the Fireteam Medic Warmind Cell mod, and Well of Life Elemental Well mod.

The only issue that I see here is the lack of an existing healing effect on Gunslingers. Giving them healing could prove dangerous in the Crucible, but it is something that would serve them well in PvE. Thankfully, we've seen more and more conditional triggers and independent scaling versus Guardians. Otherwise, perhaps a large Recovery bonus like what Well of Healing provides?

Empower: Similar to healing, empowerment seems like one of the most logical Solar effects to turn into a keyword. Grace Dawnblades are able to empower allies with Guiding Flame and Sunbreakers can boost their damage with Sun Warrior. Turning this into a keyword opens it up to other interactions and offers it to Gunslingers in some capacity. If anyone is worried about this being a nerf to Sunbreakers, I don't think it would be since Sun Warrior can be adjusted so it extends the damage boost from your weapons to other damage sources.

Temper: This is the one I have the least confidence in, but of the existing Solar abilities, the Tempered Metal, Chains of Woe, and Practice Makes Perfect weapon buffs is the only mechanic that really stands out to me as being viable for keywording. With the general trend for Solar mods to focus on "firepower", I think having Solar being the element that boosts weapons the most feels natural. There is definitely overlap with some current effects like Heart of the Pack, Turn the Tide, and Whisper of Hedrons, but not enough that I think it becomes a problem. It would pair very well with the damage bonus from empower if nothing else.

Closing

So what do you think Bungie has in store for Solar and Arc 3.0? Are there any other effects you think will become mainline abilities for the elements rather than what I've put on this list?

I'm really looking forward to these reworks. For all its Crucible problems, I really enjoy the design of the Stasis mechanics in PvE.