While color screw is a valuable and important part of Magic , its also very frustrating when it happens too often
When I found out that Zac Elsik (of Lantern Control fame/infamy) had also put work into the Turns deck, I knew there had to be something here, and that led to a fevered run with the deck on Magic Online
The mana value of a prototyped card carries over once that permanent is in play
Wurmcoil is great at providing sufficient life to keep you alive through most circumstances and is hard enough to kill that you can rely on it far more than you can with Baneslayer to be gaining you that life
Casting your own spells for free seems to be what most people do with Jeleva, according to EDHRECs stats
Zethi, Arcane Blademaster If you look on the EDHREC page for Zethi, a lot of the instants listed are already pretty efficient, but I think it makes more sense to add more expensive and impactful instants instead of copying Opt or Curate