Arena of the Ancients does shut down legendary creatures, but the effect is symmetrical, so unless you specifically craft a deck that avoids them, it's going to impact you too
Here are reprints that are worth your time: Farewell, Fractured Identity, Inspiring Refrain, Clockspinning, Lightning Greaves Foil, Arcane Signet Surge Foil, Sol Ring, Wedding Ring, Thought Vessel, As Foretold, Grasp of Fate, Deserted Beach, Fiery Islet, Glacial Fortress, Stormcarved Coast, Sundown Pass, and Sunbaked Canyon
We were in a design meeting and talking about adding flashback to the set
Thus, it's fair to say neutralizing these huge threats are just as powerful as having them on your side
Upon entering the battlefield, this commander lets you exile any number of non-land permanents you control until Abdel Adrian leaves the battlefield, creating a 1/1 Soldier for each permanent exiled this way
In Limited you don't have a limit, so you can have as many as the rest of your card pool gave you