Don't waste your ult on 1 enemy. Except when it definitly can save your life. It has a delay, so don't use it on low HP, coz you will die, while it's activating. Some champions can easily defend it, like Ghrok, Zhin. Shields also can counter it. Some others can counter ult, like Lian, Grover, Fernando. When you use your ult be sure, that they have their counter skills and ults on cooldown (use your ult just after the counter ended). It's better to not ult on a whole match than ult at the bad time, and later you miss a good moment. Use ult, when you have max ammo, and you have Rend Soul. Start to shot your ult right after you've thrown it, coz your shots need time to reach it. When the enemies will pulled in, your shots just reach them for the max damage output. Use Rend Soul asap after you collected the max (4) soul charges on the enemies. Your shots goes through the enemies and have huge hitboxes, so don't hit fully an enemy, rather shot between them for the multiply hits at the same time with the same orbs. If your enemies are on the left and the right, so you couldn't shot both with any orbs change angle after thrown it away, and stand in a line with them. After Rend Soul you can chase them down if they still could escape somehow. So go closer to them while you are ulting for being able to chase. Your ult is better, if there are an ally, who can shot the grabbed enemies too. If you have a Jenos mate make ult combos. If your Terminus just starting to Reanimate ult onto his body a little bit closer to the enmies, if there are any. If you have to ult on low HP than use Rend Soul a little bit earlier, for selfhealing before they can effect Cauterize onto you.
Mostly just useing it after their F skills and ult went out and put it between stacked enemies will help you so much. Never ult super immune champs, Like Koga, Evie or Zhin. They just can counter it whenever. And don't waste it only on tanks. If their tank is shield spammer timing your ult to right after the shield went down, or the tank will counter it.
After your ult not just chase, but use 'attack' vgs, and push them back to their spawn. You should push them too from safe positions where you are far enaugh, but you still have good sight onto their base. It's a little bit similar to the sniper spots.

@TTraw

Ok... well consider at that time Low Rez had a major issue defining the strength and dynamics of reveals. As well as, when it comes to the community providing critisism on the state of the game, many are whining baby men who only berate design without willing to discuss its dynamics, faults and feel in game, we all know the kind.

You can sort of see it right there with how they went about balencing Dark Sight giving team reveal... altering it to only reveal to self and reveal foes through stealth, that it was probably removed to streamline reveals as a whole.

When you consider you could gain 5s of reveal time off of one charge of rend soul, and one orb and pierce a crowd...
Don't you consider that just a bit too free of a reveal application for power of that duration.
You are pretty much transforming the ability into something completely different at that point.

They had tyra, strix and vivian with these light up the whole team forever revel card combos.
This power being applied far to freely for its overall power in game.
I AGREE IT WAS AN ISSUE...
But a reveal support is a need, seris is capable for it.

If you think of reveal as a form of damage and control through a debuff...
A simple kit card cannot posess that ammout of damage power to create team wide ambush pressure.

However... in base kit in a balenced format,... with a duration dependant on charges stacked, seris would spend 1.2s (+ projectile travel time) of sustained fire in order gain maximum duration of a reveal ability.
YOU ARE LEGIT TRADING EXPOSURE FOR EXPOSURE... and this is wonderful on a foe piercing supressor with stacking charges like seris with that kind of escape.

As long as this reveal has a max cap somewhere between 2-4s it should be not too hostile to work around.
Anywhere between 0.5s - 1s per rank would be suitible for the game.

Personally I think a 2s reveal is fair enough considering you can net more then one target.
I just think Seris does not have enough time to perform with it.

I am aware that a max of 4 is massivly overtoned for a concept here... its more to prove the dynamic is possible and that seris could use it.

@Jnikkibaby

The UI doesn't show decimals and it rounds up.

@TTraw I run umbral gait at 2 if i get it at all. I Don't like the champ bouncing around like shes hopped up on dope. Might consider it for a healing loadout though. Always had damage Seris in mind when considering the card. Didn't think about used to Bob and weave lol.

Added my thoughts on Seris season 3 changes. I will update the guide after testing them out on the PTS. So far, nothing exciting, wholeheartedly disappointed in no Talent Rework. No 3 stack Agony, which means it is still trash. And with reduced healing Mortal Reach will be the go-to talent 99% of the time, since Soul Collector won't sustain anything anymore. Soul Forge change is promising though.

Is the dimension of the scaling second/(detonated soul orb)?
Dusk Walker is too weak to be viable for healer or dmg Seris. I think if this card was buffed than it would be enaught to be a general escape card (Fade to Black is a healer escape card), and reload buffer card (Sorceress) could be a soul orb speed buffer, as you can see in @TTraw 's suggestion.