With the leaks of new map being flower based, it's highly likely to be a plant based agent and chamber was the previous sentinel to come out which is long time ago. Abilities, E- tree which helps to position yourself in offangles (kinda like grim walls), Q- trap plant- which traps the enemy in that position for few seconds (like fade's Q but you should place it before itself), C- flower carpet (which slows down the enemy,like sage slow), X- heals teammates to full health and gives E ability.