I've built a half-dozen or so different versions of phelddagrif over the past 7 years, so I'm probably about as experienced as it gets with the flying purple hippo. Did you have any idea in mind for how you wanted to build him? I've always focused on a political, controlly build, but I know a lot of people prefer to build him a little more...philanthropically.
If you are in the market for a political phelddagrif build you could take a look at some of my decklists, although it's definitely pretty far from a "normal" commander deck - if he likes to ramp into a bunch of big bombs, it might not be his cup of tea.
Also most versions of my phelddagrif deck have no serious wincon outside of commander damage. But I think mill is a good approach, if you want to build a political version. I would avoid cards like jace's erasure or other gradual milling though - you want to kill someone immediately once you know you want them out of the picture, and gradual mill just attracts hate from the people you're milling, and most of them won't help you control the game when you're behind. You want cards like blue sun's zenith and stroke of genius that double as card advantage or a way to kill the last opponent instantly regardless of life totals.
Of course you you could also just throw in avenger of zendikar or whatever, but that tends to run counter to the deck's usual plan of forcing your opponents to use removal against each other by providing no targets, and anything that has to sit on the board is going to be less reliable than something that can kill from hand. You could also do something like aetherling which dodges removal, but it still cares about life total. Or you could just beat down with phelddagrif without commander damage - takes a while, but you could add cards like citadel siege, evolution vat, and krasis incubation which double as removal or a way to make phelddagrif huge reasonably quickly.
One last note - phelddagrif is the greatest commander that ever was and e'er shall be and he's definitely underplayed by the plebs that don't understand his grandeur, but I wouldn't say he's obscure per se. Most people who play commander have come across him once or twice. Of course, a lot of the REALLY obscure legends are awful and not worth playing, but I think there are other legends that are significantly more obscure than phelddagrif which are still solid options - I don't think I've ever seen an isperia the inscrutable, or a jeska, warrior adept, or kaervek the merciless (except when I played him). Not to dissuade you from phelddagrif because phelddagrif is awesome, but I wouldn't expect people to go "what the hell is THAT?" when you pull out a phelddagrif deck - most reasonably experienced players will know of him.
I've built a half-dozen or so different versions of phelddagrif over the past 7 years, so I'm probably about as experienced as it gets with the flying purple hippo. Did you have any idea in mind for how you wanted to build him? I've always focused on a political, controlly build, but I know a lot of people prefer to build him a little more...philanthropically.
If you are in the market for a political phelddagrif build you could take a look at some of my decklists, although it's definitely pretty far from a "normal" commander deck - if he likes to ramp into a bunch of big bombs, it might not be his cup of tea.
Also most versions of my phelddagrif deck have no serious wincon outside of commander damage. But I think mill is a good approach, if you want to build a political version. I would avoid cards like jace's erasure or other gradual milling though - you want to kill someone immediately once you know you want them out of the picture, and gradual mill just attracts hate from the people you're milling, and most of them won't help you control the game when you're behind. You want cards like blue sun's zenith and stroke of genius that double as card advantage or a way to kill the last opponent instantly regardless of life totals.
Of course you you could also just throw in avenger of zendikar or whatever, but that tends to run counter to the deck's usual plan of forcing your opponents to use removal against each other by providing no targets, and anything that has to sit on the board is going to be less reliable than something that can kill from hand. You could also do something like aetherling which dodges removal, but it still cares about life total. Or you could just beat down with phelddagrif without commander damage - takes a while, but you could add cards like citadel siege, evolution vat, and krasis incubation which double as removal or a way to make phelddagrif huge reasonably quickly.
One last note - phelddagrif is the greatest commander that ever was and e'er shall be and he's definitely underplayed by the plebs that don't understand his grandeur, but I wouldn't say he's obscure per se. Most people who play commander have come across him once or twice. Of course, a lot of the REALLY obscure legends are awful and not worth playing, but I think there are other legends that are significantly more obscure than phelddagrif which are still solid options - I don't think I've ever seen an isperia the inscrutable, or a jeska, warrior adept, or kaervek the merciless (except when I played him). Not to dissuade you from phelddagrif because phelddagrif is awesome, but I wouldn't expect people to go "what the hell is THAT?" when you pull out a phelddagrif deck - most reasonably experienced players will know of him.
EDH Primers
Phelddagrif - Zirilan
EDH
Thrasios+Bruse - Pang - Sasaya - Wydwen - Feather - Rona - Toshiro - Sylvia+Khorvath - Geth - QMarchesa - Firesong - Athreos - Arixmethes - Isperia - Etali - Silas+Sidar - Saskia - Virtus+Gorm - Kynaios - Naban - Aryel - Mizzix - Kazuul - Tymna+Kraum - Sidar+Tymna - Ayli - Gwendlyn - Phelddagrif 4 - Liliana - Kaervek - Phelddagrif 3 - Mairsil - Scarab - Child - Phenax - Shirei - Thada - Depala - Circu - Kytheon - GrenzoHR - Phelddagrif - Reyhan+Kraum - Toshiro - Varolz - Nin - Ojutai - Tasigur - Zedruu - Uril - Edric - Wort - Zurgo - Nahiri - Grenzo - Kozilek - Yisan - Ink-Treader - Yisan - Brago - Sidisi - Toshiro - Alexi - Sygg - Brimaz - Sek'Kuar - Marchesa - Vish Kal - Iroas - Phelddagrif - Ephara - Derevi - Glissa - Wanderer - Saffi - Melek - Xiahou Dun - Lazav - Lin Sivvi - Zirilan - Glissa
PDH - Drake - Graverobber - Izzet GM - Tallowisp - Symbiote Brawl - Feather - Ugin - Jace - Scarab - Angrath - Vraska - Kumena Oathbreaker - Wrenn&6