Skyrim: Killing Arcano (Ancano) – Difficulty: Master
Wait until Arcano starts attacking you and use the Staff of Magnus on the Eye of Magnus until it loses it’s glow and becomes a “solid” sphere.
After that, just kill Arcano any way you want =).
Tip: You might wanna summon an Atronach or something to distract Arcano while you’re still working on the big sphere (sometimes those weird Magic Anomalies do that for you).
Check how it’s done in the video down below: