By Therion I'd recommend an Arrow from the Sun, Schwarzalbenheim, the Blood of Kingu, Melek Taus in addition to aforementioned.
By other bands: check out Turisas album Stand Up and Fight. It's surprisingly symphonic. Venetoi! - Prasinoi! in particular strongly reminded me of Therion. Darker bands like Bal-Sagoth, Summoning and Caladan Brood may be of interest to you.
unironically hope they do another album of retro french pop covers. i am being deathly serious. when i die i want to be interred in a mausoleum equipped with a sound system that constantly blasts opera metal renditions of jacques brel's greatest hits and causes property values in a six mile radius to hit rock fucking bottom
Dragon Rouge are also wannabes tho (like literally every living Occultist), they mix Jewish Kabbalah with Sumerian Paganism not realising those two are antagonistic forces. But bleh, you can always try maudlin of the Well for an experimental take on astral projection.
I don't like new Therion. They lost their characteristic sound... that magic and mysticism that made me discover new and ancient worlds. Now they sound cheap, empty :/ But I will always remember good times. 
I don't like new Therion. They lost their characteristic sound... that magic and mysticism that made me discover new and ancient worlds. Now they sound cheap, empty :/ But I will always remember good times.
LFDM was a bit of a lost cause, however, I think SA was brilliant for the most part... GK was terrible though, no defending that one. What made it especially lackluster in my mind was it being the follow up to L & SB, which in my mind, is the epitome of their discography thus far.
the beast of Therion is dead. I respect les fleurs du mal just for the fact that it is a deserved tribute to 60's french pop and it helps new generations get in touch with awesome artists such as Serge Gansbourg, France Gall, Victoirie Scott, among others. But that's pretty much all about it. Therion hasn't released anything worth listening to after Secret of the runes. I have mixed feelings about Lemuria and Sirius B. While I consider them good albums they feel lazily composed, filled with good but underdeveloped ideas. "A ruined orgasm" are perfect words to describe it. Gothic Kabbalah and Sitra Arah are just mediocre and half-assed at their best. Bringing this monster back from the ashes is gonna be a hard task for Mr. Johnsson.