As a part of the population who demanded this, I am very pleased. nods
I honestly find all of this pretty fascinating. In general, having tattoos specifically denote your religious affiliation, social status, etc... Sounds like such a cool concept to me. ^_^
Okay, let's try to be good and answer some questions now, then. :P
Q: In your opinion, what is the most interesting aspect of your world?
This is a tough question regarding Valcrest because every time we come up with some new bit of lore, it gains its own special place in my heart. But, I think, religion will always be the most interesting part of Valcrest. Not necessarily the mythology itself, but how the Myths and the mere concept of the Twins are so deeply ingrained in society that, frankly, being an atheist is almost considered an abomination. People don't have to be religious in Valcrest or follow a particular philosophy, but to straight up renounce the mere concept of the Twins is almost unheard of.
If you're born into a faction, in one of the cities, or are a part of any society in Valcrest, everything you know in terms of customs, rituals, beliefs, originated in the Myths somehow. From the colors you wear to what games you play as a child, to what is considered socially acceptable behavior. So for someone to come around and say they renounce the Twins as a whole is pretty much the same as saying that everything you know and love is a lie. It's a pretty big deal. So for the most part, if you're an atheist, you keep to yourself about it. >.>
Q: What is tattooing like in your world, if it's present?
This is something I've been meaning to develop for the sake of a few characters. So, surprisingly easy to answer although, I don't have much of a detailed idea of it yet.
At the time Shadows Rise takes place tattooing isn't a popular or well-known practice. It's most common amongst the military in Newhaven and the more well-traveled Crimson Shadow who got theirs outside of Valcrest. There is no such thing as a tattoo shop in Valcrest, tattoo artists are mostly self-taught nutjobs who then end up doing it for all their friends. Some of them turn out to be very skilled artists in the long run, but learning process can be awkward; to put it lightly.
Tattoos draw attention and are usually recognizable. Especially if they are colorful and/or in visible areas.
The reasons for getting them are usually personal and/or aesthetic. Likewise, placement doesn't hold much meaning, although amongst the Black Guard it is a somewhat standard practice that if you get a tattoo in honor of a deceased loved one, it should be placed on your back. This is both to symbolize them becoming a part of your past and the idea that they still "have your back" even in death, as this is usually done in honor of fallen squad members.
Around the time the main series kicks in, tattooing is a bit more common, but still not something very accessible. You can find people who will do it for coin, but you have to really look to find it. It'd be frowned upon in Blackpond to some extent as most things to come out of Newhaven's customs, but tattoos in honor of their military or War himself would be a little more accepted.
Q: Is there something in your world that is illegal/frowned upon, simply because it's associated with a certain/culture/religion/enemy nation, etc...? (As an example, it's illegal to promote or participate in chess tournaments in Newhaven :P)