Mercenary: Flash of Blades

 is a challenge in Risk of Rain 2. It is completed as by using 20 abilities in 10 seconds.

Tips

 * This can be achieved without a single item and when using the default loadout. While fighting a tightly-packed group of enemies, holding left click to attack continuously and applying Expose to as many enemies as possible can recharge quickly enough to reach the number of attacks required.
 * With 4 or more, Mercenary's primary attack speed becomes fast enough to complete the challenge.
 * This is also possible when equipped with, since each individual shot counts as one ability and they stack up to 12.
 * and allow stacking uses of secondary and utility attacks. Having enough makes this challenge trivial.
 * allow the player to repeatedly use abilities for a short time after slaying an Elite.
 * As with most challenges, the makes it easy to get the items you need.
 * It is also possible to complete the challenge between runs by continuously restarting runs after spamming many abilities, since the challenge only counts in-game time and does not reset the counter after each run.