Its a Commander variant inspired by the legend of King Arthur and Excalibur, where you pick a common creature to be your champion (commander) and a legendary Equipment to be its signature weapon
It is a great mana sink, quite a scary top end threat and a fine mid level filler card that can deal with some pesky little dorks
A bold claim, I know, but lets take a moment to compare Deep Gnome Terramancer to most of whites other mana ramp spells: You dont need to be behind your opponents in land count to trigger this ability There arent any extra mana costs you have to pay for this mana ramp effect (and unlike treasure generators, this ramp is also more permanent) Deep Gnome Terramancer only costs 2 mana, putting it on par with the rate found on many of greens best ramp spells Like Natures Lore and Three Visits, you can fetch nonbasic Plains cards like Jetmirs Garden The condition for this cards effect happens all the time in Commander, and can be found on cards in most decks of any power level your opponents are playing even precons
These Secret Lair variants are likely to be worth a bit more across the board
You can go wide with your fodder creatures, all the while building up Syr Vondam for a big commander damage finish