You may just have a small fortune on your hands
Edge of Eternities Stellar Sights bonus sheet contains lands from all throughout Magic's history
Until end of turn, that player cant cast spells, you may look at the top card of their library any time, you may play the top card of their library, and you may spend mana as though it were mana of any color to cast spells this way
Honestly, the plus one alone would probably be enough to make this fantastic, since card draw is so in-demand in Commander
Granted, it's tapped Treasure, and it's gated to once per turn, but that's only fair given you can convert your stash of Treasure tokens into 4/4 fliers with haste
When Aerith Gainsborough dies, put X +1/+1 counters on each legendary creature you control, where X is the number of +1/+1 counters on Aerith Gainsborough