Wow, that actually sounds like a really cool idea, like a duelist with extra mobility? Like Spiderman, maybe? Also can the grappling hook grapple enemies to pull them closer, and also can it interact with objects like grabbing a gun or grabbing the spike. This can also easily become too OP, with the player with the grappling hook being able to continuously grapple to climb up walls and structures that should not be climbable. But a workaround for this is to only make certain surfaces climbable or only let the grapple latch onto certain angles (like it has to be flat or at an angle and not straight up and down so it cannot grapple on wall. Also another question is can the agent stay there? Can an agent swing on the grappling hook to gain extra momentum and move very fast at the cost of possibly instantly dying from fall damage? If the agent can, they will be able to hold some crazy off-angles, and this, in the end would make Valorant, well, less like Valorant, since it will be more up-and-down than left and right, and traditional crosshair placement would be even less effective.
But of course, all of this can be changed to keep this agent balanced with the rest of the game, such as by reducing the range and speed of the grappling hook, or how many charges it could be used before it breaks, or how many times it could be used in succession before it is disabled/breaks. But all in all. this actually sounds like a really cool idea, and I can already see a lot of creative uses and plays and lineups with such a fresh mechanic, and I personally would really want to play an agent who's like this. I would definitely like to see this agent fleshed out more, with an appearance, personality, and backstory, as well as more fleshed-out different abilities and an ult. But no pressure tho, I just thought this was really cool.