You need a lv6 omni with aghanim. At lv6 he can buffs 100% magic resistance, which makes the targets he buffs become immute to status effects. His agh turns the skill into aoe so that he can buff multiple targets at once, so it's necessary to have agh. Also, even after agh upgrade, his skill still considered single target so you can can increase his cast range with item.
And its really nice to have a lv6 onmi with agh because your towers no longer get debuffed by creeps' abilities(stun, decrease mana regen, slow...)

Use 2 str Morphings or Witch doctors with SOME scopes around. You can stun her everywhere on the map. Lvl6 omni with agha's safer but your team will be lack of damage.

Yeah, start to building WD after wave 40 ish, lv 3-4 is enough, perfect for duel boss and also good for 3 boss after 100 waves. Also realized Morphings is significantly better for Naga or magic immunity boss, remember to change it to Strength

i use 2 aghm-BANE via 3aether lens kill him