The cube looks fine, although I'm sure you are aware that you're running a number of under powered cards (Seraph of Dawn etc.). You also seem to be running a lot of black removal spells, even for a 720 card cube. Consider cutting Eyblight's Ending and Hideous End at the least. In fact, cut Rend Flesh too and get Diabolic Edict in there.
I would consider cutting Sol Ring though. It really doesn't have a place in that kind of environment. Sure, it doesn't win every game, but it will stick out like a sore thumb in your cube.
Also, 10-11 non-land cards in each multicolour section also seems too much, even for 720. I run 5 in each section in my 500 card cube, and would probably go to 7 in a 720.
Also, your average CMC is pretty high in general in your mono-color sections. Most of the advice that you hear bandied about is to keep the average CMC at or under 3. You could easily get there by cutting some of your weaker high-cost spells like Ulamog's Crusher and Ojutai, Soul of Winter. Thin out the top end of the mono-color sections too. You don't need four white 6-drops and five white 7-drops for example. They sound fun to play, but what they end up doing is bogging down peoples' decks.
I'm new at this too, but those are my thoughts for what they're worth.
Looking for and and all advice on my Vintage cube (CubeTutor Link)
All feedback is welcome. Thank you!
Juju Alters - Altered MTG Cards
Although it's Unpowered, it contains cards banned in Legacy, such as Demonic Tutor, Channel, etc. Hence, it's a Vintage cube.
I would consider cutting Sol Ring though. It really doesn't have a place in that kind of environment. Sure, it doesn't win every game, but it will stick out like a sore thumb in your cube.
Also, 10-11 non-land cards in each multicolour section also seems too much, even for 720. I run 5 in each section in my 500 card cube, and would probably go to 7 in a 720.
Juju Alters - Altered MTG Cards
Also, your average CMC is pretty high in general in your mono-color sections. Most of the advice that you hear bandied about is to keep the average CMC at or under 3. You could easily get there by cutting some of your weaker high-cost spells like Ulamog's Crusher and Ojutai, Soul of Winter. Thin out the top end of the mono-color sections too. You don't need four white 6-drops and five white 7-drops for example. They sound fun to play, but what they end up doing is bogging down peoples' decks.
I'm new at this too, but those are my thoughts for what they're worth.