How do you defeat the antagonist of the Eye of Magnus quest?

I just completed the final (I think) main quest of the College of Winterhold and became the Arch-Mage, although I have no idea how I did it. Nothing I did seemed to be having any effect, either on the Eye of Magnus, or on Ancano. Eventually, Ancano simply keeled over and was dead.

I was shooting the staff all over the place, so I'm not sure which target had an effect and which completely ignored my attempts.

What is the intended way to claim victory in this battle?

Solution 1:

You're supposed to close the eye with the staff, which makes Ancano vulnerable. Then you can kill him however you wish. I found the staff to be more than adequate for this.

Solution 2:

From the Unofficial Elder Scrolls Pages wiki, "The Eye of Magnus" article (important parts emphasized by me):

Ancano and Tolfdir will talk for a short time before Tolfdir launches a spell at him, but with no effect. Tolfdir is knocked down and remains incapacitated while Ancano attacks. He will still have his protective barrier, which can be removed by using the Staff of Magnus on the Eye of Magnus.

It is important to use the Staff for a sufficient amount of time on the Eye of Magnus- until it returns to a solid, non-glowing sphere - because the protective barrier gives Ancano near immunity to magic and physical attacks when the Eye of Magnusis only partially weakened. When the glow surrounding Ancano dissipates he will be vulnerable to attacks.

During the fight he may approach the Eye and regain his protective barrier, which must be removed again. When the Eye separates into several hovering and rotating pieces, it is gaining strength, so Magic Anomalies may appear; be sure to use the staff on the Eye, so as to get it to lose more power and return to its original form for some time. The Magic Anomalies will yield soul gems when killed, allowing the Staff of Magnus to be recharged if it depletes during the battle. It is possible to leave Ancano to fight the magic anomalies and get himself killed that way, as they will attack him as well.

When Ancano is defeated several members of the Psijic Order will appear once more. The player is congratulated on their efforts, and declared worthy of being the new Arch-Mage. They will also state that the Eye of Magnus is unstable, and too dangerous for this world. Shortly after they will vanish in a glow of light, along with the Eye.

Solution 3:

I defeated Ancano by :

• Activating the Eye of magnus with the Magnus staff (the eye opens in reaction to this)
• At some point, Ancano stop focusing on the eye and begins attacking you
• This is when you use this great anti-mage staff you just acquire to drain his magicka and health.

Solution 4:

You dont use the staff on him you use it to SHUT the eye , when the eye is open Arcano will not take any damage. You are even told to use the staff on the eye. It becomes EXTREMELY easy to kill him off if you make sure the eye gets CLOSED when ever it is opened by Arcano.

Solution 5:

I waited until he finished his speach and then shut the eye using the staff of Magnus. After that I used the "Ice Form" shout to freeze him solid to keep him from dodging my battle axe, since I'm really a nord two-handed/heavy armor type.