Personally I do not like blood and sacrificing theme as a headline of a new civ. We have already bloodthirsters as well as sacrificers.

And we have already agnostic Grigory and Illians whith their religious specificity so it is better to make Liz able to adopt any religion: strategy play comes from combinations.
Jungle and marsh is better. As they are reptiles they need very specific conditions. So nice to see them like following (strongly revolutionary

).
- L can not settle or work tiles without access to fresh water as well as tundra, ice and desert tiles.
- L workers can terraform tiles with access to fresh water into marsh (except of hills, Ice, tundra and desert but including flood plains/desert and oasis/desert).
- Marsh grants fresh water to adjacent tiles.
- L have +2 food from jungles and 4 food from marsh.
- L can build farms, cottages, pastures and plantations only on marsh.
- All L units are building with food.
- Starting from Sanitation L workers are able to build jungles.
- L have no unhealthiness from population.
- L can hurry buildings by sacrifice population under any civics with no happiness penalty.
- L workers are unable to build mine or workshop.
- L units has positive affinity to marsh and jungles and negative to Ice, tundra and desert.
- Marsh can be turned by scorch to grasslands.
- L units can not have metal weapon promotions. For all metal weapon units they have replacements with higher base strength as a result of genetic engineering, not metallurgy.

- L have no access to arcane fire magic.
- L workers can not build roads.
- L can use marsh for trade routes.
- L units have huge bonus on marsh movement which grows with techs researched.
- Other civ units can not move across marsh without road before construction.
- After construction they can move not more then 1 tile per turn (without a road).
I assume that marsh is a terrain and jungle is a terrain feature which may be grown on marsh.
etc.