Svarog is a destruction character that focuses on dmg reduction and counter attacks, befitting of a destruction-type survivability character. As of version 3.8, he has no analog in Genshin. The only counter type characters so far are Yun Jin, Beidou, Candace. And then Dehya and c6 zhongli have similar mechanics where if the character takes damage, they absorb damage and heal.
But Genshin could design a similar kind of character as Svarog (call it S): when the enemy deals damage to S, S will reduce the damage by 10% and then immediately counter the enemy (can be single target like hyperbloom shot, like having a robot fire rockets at enemies) and mark the enemy (think Childe or Nahida type mark). This effect can occur once every 1-2s, and it is a passive talent that is always in effect. If you want, you can put a limit on how many enemies can be marked (e.g. 8 like for Nahida's skandha E).
Then the E skill of S will deal aoe damage as well as additional damage to all enemies affected by the counter mark, while clearing the mark from them (like how Childe's melee Q can clear riptide). The Q burst of S will further reduce damage to S by 30% (for 10-15s). Moreover, whenever any character is attacked (not just S), S will make an enhanced counter (does aoe damage and increased damage) and apply marks on enemies. The enhanced counter can occur 2-5 times while the burst is active.
One thing that Genshin does not quite have is increasing a character's own aggro (taunt). Genshin does have taunts like Mona's mirror, Amber's bunny, or Ushi. However those make the enemy attack things other than the character. By default, enemies will attack the active character. There are not 4 characters on the field at a time (in single player). So there is no use in making enemies more likely to attack S in Genshin.
Instead, S can have a Dehya-type passive, whereby whenever the active character is attacked, there is damage sharing, or part/all of the damage has a probability to go to S. Then the Q can increase the probability that the damage goes to S.
How to handle shields? If the enemy attacks a shielded character, just treat it as if the character took damage. There is still the same probability part/all of the damage goes to S. S would probably work well with a shielding / preservation character. Otherwise, S may need to provide some extra poise / interruption resistance (like Dehya E) as enemy attacks can knock the player around. Perhaps S may need to give infinite poise to work very well. The whole point of S is to get hit as much as possible, and without having close to infinite poise, it may be inevitable that the player will get knocked around like how Scaramouche can be knocked around in air (lack of friction with ground).
In Genshin, S would be a kind of sub-dps character that does automatic attacks. But all of these are reactive, contingent on the enemy attacking the player. So one runs into the 'hit me' situation that Beidou is sometimes in. Certain enemies like the elemental crocodiles and tigers of Sumeru attack very frequently, giving more opportunities for these kind of reactive characters. Burning and bloom can also deal damage over time to the current player. Dehya and c6 zhongli also rely on getting hit for certain effects to proc, as well as the amrita/vourukasha artifact set.
The fact Genshin introduced Dehya, who has this damage sharing ability, indicates Genshin is trying to bring more destruction type characters into the game. As shown by Xiao or Itto, destruction characters can be extremely powerful compared to standard erudition or hunt class characters.
What element should S be? It actually may not matter. As stated above, S is a sub-dps that can potentially do continuous damage off field. This could make her compete as an off-field elemental applicator (without need of Q). So we can see which elements are in need of such a subdps. Electro currently is saturated with several E applicators (Raiden, Yae, Kuki). Dendro has Nahida and Yaoyao. Geo has Albedo. Hydro and Pyro have characters like Dehya, Kokomi, Nilou. There is potential to make S hydro or pyro to have something with 100% uptime at C0. Cryo lacks such a subdps, so making S cryo could be good too for melt, freeze. Anemo also lacks an E subdps, so making S anemo could help with constant vv application.
So if S is anemo or cryo, that can increase the value of S the most. Making S hydro or pyro would also be ok. And then making S electro, dendro, or geo would be redundant and would reflect badly of Svarog's reputation. But of course, Genshin sometimes does things to damage certain characters' reputations, so it is not out of the question.
Weapon? It may not matter as in the case of Svarog, it is the robot doing the damage. The weapon could just be for show. The NA of S could just be a robot punching things. For example, Dehya makes a punch with one of her NA. That said, S would probably be a melee character if they rely on a robot to deal damage, so perhaps sword, claymore, or even polearm. But nothing is definite, they could be bow or catalyst too.
Constellations? Look at Svarog's constellations for more ideas. Special dish? Birthday? Why are you asking these questions here?
It is possible that S may not even deal any damage. If the character dodges all attacks or if the enemy fails to hit the player, then S will not counter. But this is the case in HSR too. If the enemy does not attack Svarog, then Svarog will not counter. This is a case where the dps output of Svarog / S is close to 0. So this is what is meant when characters like Svarog and Luocha are reactive. How to deal with this?
Given that Nahida, Yae, Albedo can do a lot of damage automatically, the only saving grace of S is if their counter does a ton of damage. This is to compensate for the possibility that the counter may not proc if they enemy does not hit the player.
In that case, what is the point of using this counter mechanic? Why not just make the subdps automatic, deterministic, and periodic like Yae's E? And if a Svarog-type character is supposed to provide damage reduction (survivability) then why not just use a preservation unit / shielder? Such questions are basically questioning why a character like Svarog exists in HSR. Shielding units typically do not do much damage on their own, and dps units typically do not provide much defense to the team (characters like Itto with high def and access to crystallize shields are few and far in between). So the idea is to combine both roles into a single character (this is the point of many destruction characters): to have a single unit that can tank damage while also dealing more damage than a typical preservation unit.
If S cannot even deal decent damage, there is no point to have such a character. So in what range should the scalings be? For comparison, each of Yae's turrets (E) has around 170% scaling (lv10). Xiangling's Q has around 200% scaling per hit (without melt/vape). Both Yae E and XL Q are automatic and periodic, whereas the counters of S are not. So if counters can be procced once every 1s, then the scaling should at least be around 200% per counter (regardless of element given that XL is pyro and still has 200% scaling).
And then the enhanced counter from Q can add another 200% scaling per counter (total 400% scaling), similar to Beidou's counter. Or it can provide increased dmg bonus (like Xiao, Yanfei Q). Many have observed that Beidou's E can nuke, so imagine creating a character that makes counters the basis of their dps. This is the idea behind S.
These scalings are to make S at least somewhat competitive. Of course, nothing is stopping Genshin from using punitive measures to make a character underwhelming deliberately (like tighnari, baizhu).
Even if Genshin does not create a Svarog clone, that does not stop other games from using such an idea to create their own kind of Svarog. The point of this thought experiment is to imagine what such a Svarog-type character would look like in a Genshin-type game (3d open world with dynamic non-turn-based combat).
Whether the Svarog-type character is an original invention of HSR or based on something from another turn-based game like final fantasy is not the subject of this article. That discussion is left for other people.
The name of Svarog's technique 'A Small Price for Victory' epitomizes what the path of destruction is about. I will make a little sacrifice, even have others attack me a little bit, but in return I deal more counterattack damage against them. So this is a kind of sacrifice to make to win the battle. Other kinds of characters make different sacrifices such as sacrificing their hp (Arlan, Blade). But the philosophy is similar: an eye for an eye, but with a caveat, you hit me, but I hit you back harder. A different kind of philosophy is the inversion of this: win-win, but with a caveat, I help you win, but I win much more. This is a bit different from harmony, which seeks to buff the whole team.