Destiny 2: Solo Ascendant Challenge Underleveled (Max Corruption)

I was LL 537, running an IKELOS SG, Sleeper Simulant, and a god roll Ten Paces (Drop Mag, Triple Tap, Rampage).
I tried meleeing the invincible knight beforehand for the empowering buff but I misjudged and attacked the wrong one. Either way it's unlikely that Empowerment would have lasted to the stage where he gets up and is aggro'd.
I previously tried this with a Devour Warlock, but was unable to make pace due to the fact that while Devour can run infinitely as opposed to Well of Radiance's 30 seconds, it provides no damage buff and against the two knights, you're screwed. Well of Radiance is definitely the way to go.
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