Graveyard & Reanimation: Angel of Glorys Rise, Ephemerate, Gift of Doom, and Devout Chaplain offer recursion and protection
The scary thing about Olivia is that, if she can keep swinging, you can keep bringing creatures into play from the graveyard
Pretty much all of Lord of the Rings fit seamlessly into Magic, right down to the depiction of creatures like Orcs and Goblins
While not exactly game-breaking, attacking opponents' hands can be decently disruptive and is deliciously mechanically Grixis
Cards like Glimpse of Nature, The Great Henge, and Beast Whisperer reward casting creatures with card draw, and they often see play alongside mana acceleration
Say what you like about old-school EDH, but this ban was deserved at the time