Edgar's last ability will apply to each of those five flips, meaning they'll all come up heads and you'll take five extra turns as a result
Sarkhan, Wanderer to Shiv could have a home in five-color Dragons just because the +1 is an absurdly powerful source of ramp and color fixing, but Historic Dragons already have a lot of ramp, between Sarkhan, Fireblood, Dragon's Hoard, and now Orb of Dragonkind, all being cheaper than Sarkhan, Wanderer to Shiv and offering card advantage that doesn't involve you casting Shivan Dragons in Historic
It's Nature's RhythmNature's Rhythm that takes the crown
You can do something similar with Warp cards and a sacrifice outlet
Additionally, Voice creates attacking tokens each turn that synergize nicely with some of the top cEDH Commanders