Tinkering around with using themes from planescape for legendary sagas. I'm not sure if the last ability is actually "meh" in-format, but I did sort of set up the other abilities to give you a big leg up against your opponents. Out-format it is potentially quite powerful if not auto-win.

A legendary themed set overlaps well with commander, so the rider at the beginning is nice I think.

The second ability is outside black's slice of the color pie.

The first ability has no duration given. 'Spells your opponents cast this turn cost an additional "Pay 2 life." to cast.'?

Life setting abilities like Biorhythm are obnoxious in Commander and IIRC that card is/used to be banned for that very reason. Bad call to put that kind of effect on the enchantment of all options that you not only design for Commander/EDH, but also make explicitly available as a commander, so drawing/tutoring it is not even a challenge.

The Blood War is certainly a concept that would make for a nice mythic rare enchantment (does it have a timeline that translates well to the Saga template? I only know it as "that ongoing thing" with no clear concept of chapters/phases), but this card doesn't seem to be it.

It would work more as , you're right.

The first ability is sort of that way on purpose, sort of meant to carry over into the next two phases, more like a regular enchantment effect. Maybe that goes against the rules of how sagas work and I wasn't aware?

The Blood War is sort of an eternally on-going thing, but I figured this could represent an "episode" of it, so to speak.

But yea this was sort of a wild experiment. I like the idea of a saga being able to be your commander more than anything here.

I intend to develop some on-theme sagas at uncommon, rare, and mythic. I'll have to feel out how to go about that and it's definitely an important item on the list next to legendary lands and gates.