We recommend that you try the encounter blind -- You'll hopefully find it a lot of fun. But if you want to keep reading and get the strategy, keep reading.
? (Normal) Mechanics
Ky'veza only has 4 mechanics that she uses, but ALL of them will one-shot the player if handled incorrectly. There is only one phase, and there is no enrage timer. After each cycle, Kyveza gains one stack of Death Cloak, but this is nothing as the majority of the time you'll likely be dying to a one-shot.
Nexus Daggers -> Nether Rift -> Dark Massacre -> Nexus Daggers -> Nether Rift -> Dark Massacre -> Nexus Daggers -> Invoke the Shadows
Slow and steady wins the race on this boss.
Nexus Daggers
Ky'veza uses Nexus Daggers trying an arc of 5 daggers on the ground and then summon clones which will sequentially throw daggers on the ground as well. These fire relatively quickly and can overlap.
The trick is the middle dagger will always be on top of you. Their hitboxes are relatively tight and thus slow steps between each dagger will help you stay alive.
Nether Rift
Ky'veza summons clones one at a time, which will then charge through the player. If the player is looking at the clone, you live. If you're not looking at the clone, you take lethal damage.
Dark Massacre
Ky'veza targets the player, Brann and a random spot on the ground. After a few seconds, a portal will land on the ground there and sucking all players in. You want to spread the portals around the arena, so the pull effects cancel out.
Two of the points are fixed with Brann jumping to one location, and the random portal. Thus, you want to be the 3rd point of a triangle and then stand in the middle with all of them.
Invoke the Shadows
At the end of a cycle, Ky'veza summons 5 clones on the points of the hexagon before teleporting into the 6th position. The clones will then shuffle and players will have to click the correct Ky'veza to continue the fight. When the clones stop shuffling, they cast Shadow Eruption for 3 seconds and if the cast finishes before Ky'veza is found, the player dies.
?? (Hard) Ky'veza
There are no additional abilities on this difficulty. The boss has more health, deals more damage and all of Kyveza's abilities have been upgraded. Since everything one-shots, its key to take your time. Slow and steady definitely wins this race as nothing changes over the encounter.
As of right now, this fight is only really possible on a Tank as DPS specs will die to unavoidable damage. This boss will take 6-7 cycles where she will be doing bonus damage due to Death Cloak.
Here are the changes to the encounter:
Nexus Daggers fires 7 sets of daggers (was 5), with less time between dagger shots and with a faster cast time.
Nether Rift now has a piece slice ground effect that limits where you can place the Rift. This honestly doesn't do much.
Dark Massacre summons 6 clones (was 3) and you have to look pretty much directly at the clone to survive.
Invoke the Shadows now shuffles 12 times (was 8) and the shuffle is faster.
Below is one of the clone phases on the Hard Mode difficulty. Can you follow along?
