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.