Alright, I have some time to update here, so I will. I think it's time to elaborate on the things I learned and the abilities I gained during my time with Vassago.
First off, the reason I entered Vassago's tutelage, the runecraft. Some basic thing about runecraft, first, I think. First off, the things I already knew. Runes are basically writing enforcing a person's will, but there is one thing that makes it so you can't just write down "Explodes when someone touches it" on a rock and it works as described. Only certain alphabets function in runecraft, specifically ones passed on from gods. In other words, the speech of the gods , which already carried immense power, continues to in runes.
That said, the runes' function is determined by two things. The first is what is written. For example, a textbook explosive rune would read as something similar to "round fire wind". The other determining factor is the intent behind the rune. The "round fire wind" runeset could be used for an explosion, or as a circular wall of flame, all depending on how the runecrafter wants the glyph to function.
Part of the rune's strength and longevity is in how it is written. A sharpie-on-paper runeset might be quick, but it will not last long, nor will it be particularly strong. A rune carved into solid diamond, however, will last neigh-forever, and be extremely potent.
Another point to make is that runes don't last forever. The willpower the crafter put into them eventually wears out, much like a battery. Thus, some runes, like a durable explosion rune, must be recharged after each use. This can come in handy with the "round fire wind" runeset, because you can change the usage each time you charge it.
One perceived weakness of runes is that most of them, unless otherwise crafted, glow. This is a misconception in many cases. Runes that cause a direct physical effect, such as wings, appendages, and elevators (I've been having fun the last few days), function better when glowing, the light serving as a radiant force. Glowing glyphs also have the advantage of not having to be set on a solid object, the light serving as its own medium.
Something else to take into account is that simple glyphs can be effective, but more complex ones can be even more so, but even more important, complex ones can be safer. The difference between "explode on contact" and "explode on contact with living being" is huge. Crafting at one symbol a minute, the explode on contact takes about an hour, while the contact with living creature glyph would take about a day of nonstop carving. If you were to be as specific as "explode on contact with human being," you're looking at about a week. I won't even get into specific people.
As far as charging / recharging goes, the benchmark for time is around one second per letter, but that can change with the crafter's willpower. Additionally, it can only be charged with someone who had a hand in carving it. If it is charged by someone who didn't carve any of it, the glyph rejects the will, resulting in what could be functionally called feedback. For an idea as to what the feedback would feel like, put a very loud, very high-pitched klaxon on your mp3 player, set it to loop, and stare into a strobe light for an hour while listening to it.
Even more interesting is if a glyph is charged by one of its crafters, but charged with an incorrect intention. The glyph accepts the will, and interprets the will as best as possible in the context of the writing. If I were to take my "round fire wind" glyph and charge it with the intention of "pour water," the result would be something along the lines of a sprinkler. Spraying lava. It's a handy way to trip up other runecrafters, providing it doesn't (sometimes literally) backfire. Messing with alternate interpretations should be approached in the same way as a literal djinn, not at all, under any circumstances, ever.
That's all I can think of for now, so I will comment on the most interesting side effect of my trip to Hell. I noted before how my perception of time was roughly fifty-two times the speed of reality at large, meaning I lived a year in the space of a week. This perception of time, or rather, the ability to shift into it, stayed with me when I returned. I have retained the ability to enter bullet-time. This comes in extremely handy when I am crafting, as I can carve a week-long rune in approximately three and a half hours.
Also, I have wings. Glowing, rune-y, angelic wings. I love them. So does Lucia.
Life is good.