Internet ate my long post. Twice.
I can summon a blood SC per turn too if I want. Latelly I was invoking 10+ demon knights and 20+ Devils per turn, as well as Enliving Statues and some Vine chaff to reduce the gap in total troops.
I have several SC too, including my god, a Heliophagus, a couple Fire Devils, awakened golems, awakened Eater of deads, a Djinn, and Elemental Kings. I can as well summon angels, including Seraphs. Most of them can be a challenge for Tartarians, specially if they use AntiUndead weaponry such as Flamebeaus or herald lances, etc.
I have also a very large amount of comunion-able thunderstrikers and a dozen bow of wars with quicken self that can shoot 600 high precision flaming arrows per turn, which might be powerful even against arrow fends, I suppose. Every single LA Marignon mage can comunion or sabbath, which is somewhat cool too.
The problem is I'm facing not only tartarians. I'm facing 3vs1, so it's a moot point to try to defend. I can hold my own for a couple of turns at best, you only need to attack every singlen province I own without a castle and I'll colapse. Also, Atlantis is already winning, he generates as much gems as everybody else combined, and in the late game, gems are the thing that matter. If we would face him 3vs1, it would be a coin toss. In any other situation, it's just pointless to keep the game running for another month or two just to wait for the inevitable.
I also learned a lot in this game. Diplomacy is not the most important thing. It's the only important thing. Patala faced 2vs1 and died (with me taking late spoils of war), Jomon faced 2vs1 and died (with Gath being the late robber), and now I face 3vs1. If I should have joined Atlantis half a dozen turns ago when he was asking me to attack someone, I might have got a chance, but I thought he was already winning too much. However, I did not join him, but I did not plot against him either, and that's a heavy mistake.
Overall, nice learning game.