It depends on your support skills.
If you have anatomy or tactics (anatomy more likely as a mage, if you have healing skill), you will get better damage.
You're more likely to beat it if you have high DI on the weapon as well. Slayer weapon is your best bet, a mage weapon earth ele slayer with high DI even better. Speed is not important - in fact, a slow, heavy-hitting bow like an elven composite, Yumi or heavy crossbow will do you better than a fast one, IMO. This is especially true for melee weapons - slower swing speeds will encourage you to back out and heal between passes in hit and run, as opposed to standing toe to toe for multiple hits (and possibly kill yourself).
While your summons can't hurt it, if you get the val to target them (by going invis after ordering them to attack), you'll be able to inflict more damage with less chance of being target of both direct damage and your damage reflected.
