Lay a trap for Emerald

Ruby had been spying on Emerald and her team for a while to find a way to get payback. Ruby had devised a plan to lay a trap for the Green haired assassin as she wants her to feel the same embarrassment as her partner only 10 times more, safe to say that she ain't that forgiving for Emerald had done.

And so, her plan is that she will sneak in their room to sabotage Emerald as she tampered her clothes by using a special kind of timed corrosion dust, while she may not be as good with dust as someone like Weiss, she is still a prodigy in her years and with the help of the humiliated Heiress, she can make some interesting dust types for her bullets or in this case, to make an elaborate prank. The corrosion dust has its own timer or a special way to activate under a certain circumstance which is perfect for her objective.

And so after some setting up and looking at their team's schedule, she knows where and when to set the trap for the unsuspecting assassin.