In Commander, where people run plenty of shocks, triomes, and especially dual lands, Fellwar Stone frequently turns into a two mana rainbow rock
Not bad for a combo that you can feasibly play on turn 3
But, her first ability lets us impulse draw the top card of our library whenever we cast our second spell each turn and her second ability lets us copy an instant or sorcery spell we cast (as long as we've cast 3 or more spells that turn)
It was both competitive and fun to play much to my surprise
Decklist Deck 8 Forest (FIN) 306 8 Island (FIN) 297 1 Capital City (FIN) 274 3 Guadosalam, Farplane Gateway (FIN) 281 2 Crossroads Village (FIN) 276 2 Terramorphic Expanse (J25) 156 3 Bushwhack (FDN) 215 1 The Earth Crystal (FIN) 184 1 Travel the Overworld (FIN) 82 2 Traveling Chocobo (FIN) 210 2 Prishe's Wanderings (FIN) 193 1 Reach the Horizon (FIN) 195 2 Bristly Bill, Spine Sower (OTJ) 157 3 Sazh's Chocobo (FIN) 200 2 Ride the Shoopuf (FIN) 197 2 Sidequest: Raise a Chocobo (FIN) 201 1 Bartz and Boko (FIN) 175 2 Mossborn Hydra (FDN) 107 3 Chocobo Kick (FIN) 178 2 You're Not Alone (FIN) 44 2 Choco, Seeker of Paradise (FIN) 215 2 Summon: Fenrir (FIN) 203 2 Gysahl Greens (FIN) 190 1 Sazh Katzroy (FIN) 199 2 Ambrosia Whiteheart (FIN) 6 This is the most fun I've had with a card game in a long time so much so that I jumped into MTG Arena's ranked mode and found enough success to place in high gold for the season

These things combined mean that Dredge can potentially mulligan three or four times to look for key cards, and still have a great chance to win many of those games