Wielki Hegemon
Emperor
I stick to the concept of one city Civilization. In Civilization VI supporting rather a wide empire style, it was quite of a challenge. So I decided to give them a large overpowered district and some catch-up mechanics. This is the result:
Enrico Dandolo leads Venice in Civilization VI:
Unique Ability
"Serenissima"
Cannot build settlers and districts outside Capital.
Can purchase districts with Gold. Also, 30% production cost of World Wonders can be purchased with Gold.
Free Trader unit after research Foreign Trade and +1 Trade Route after research Naval Tradition
+1 Culture and +1 Science from Trade Routes
2 governors can be assigned to Your Capital.
Leader Ability
Crusade Merchant Army
Units cost 30% Gold less.
Every 30 turns you can buy one of three random Unique Units from actual Era with 50% Gold less.
For example in Ancient Era (Eagle Warrior, Hoplite, Maryannu Chariot Archer, Okihtcitaw, Pitali Archer, Viking Longship, War-Cart) you will have to choose one from Eagle Warrior, Maryannu Chariot Archer or Viking Longship for 50% Gold cost. So Eagle Warrior would cost 130 Gold.
Unique Unit
Venetian Mechrant
Replaces settler. Has two charges. Can build Venetian Trade Forts
Unique District
Canale Grande
Replaces the Neighborhood and must be built on Marsh, Coastal title or title adjacent to City Center.
Available earlier with Naval Tradition.
Yield does not change based on the tile's Appeal.
+4 housing, +4 Gold, +4 Science, +4 Culture, +4 Great Works slots, and +1 Amenities. +4 tourism after Cultural Heritage
Acts like Canal.
Gives adjacency bonus as City Center.
What is the Venetian Trade Fort?
1. Venetian Trade Fort is a sort of unique title improvement. You can build neither buildings nor districts in Trade Fort. Trade Fort don't have a population, housing etc.
2. Venetian Trade Fort has one title reach and can not grow. Builders and Military Engineers can improve titles belonging to Trade Post.
3. Venetian Trade Fort can only be built in Coastal title
4. Venetian Trade Fort must be built on neutral territory
5. Loyalty does not affect Venetian Trade Fort.
6. Venetian Trade Fort gives all Faith, Science, Gold, and Culture from titles belonging to Venetian Trade Fort to Your Capital.
It also provides +1 Food and +1 Production to your Capital for every 6 Food and 6 Production from titles belonging to Venetian Trade Fort.
7. Venetian Trade Fort provides all Luxury and Strategic resources from improved titles belonging to the Trade Post.
8. Venetian Trade Fort has Base City strength and Ranged Attack.
9. An enemy can not keep Venetian Trade Fort after conquering it. It will be always razed.
10. You can not assign Governor to Venetian Trade Fort
11. Each Venetian Trade Fort has a unique name.

Enrico Dandolo leads Venice in Civilization VI:

Unique Ability
"Serenissima"
Cannot build settlers and districts outside Capital.
Can purchase districts with Gold. Also, 30% production cost of World Wonders can be purchased with Gold.
Free Trader unit after research Foreign Trade and +1 Trade Route after research Naval Tradition
+1 Culture and +1 Science from Trade Routes
2 governors can be assigned to Your Capital.
Leader Ability
Crusade Merchant Army
Units cost 30% Gold less.
Every 30 turns you can buy one of three random Unique Units from actual Era with 50% Gold less.
For example in Ancient Era (Eagle Warrior, Hoplite, Maryannu Chariot Archer, Okihtcitaw, Pitali Archer, Viking Longship, War-Cart) you will have to choose one from Eagle Warrior, Maryannu Chariot Archer or Viking Longship for 50% Gold cost. So Eagle Warrior would cost 130 Gold.
Unique Unit
Venetian Mechrant
Replaces settler. Has two charges. Can build Venetian Trade Forts
Unique District
Canale Grande
Replaces the Neighborhood and must be built on Marsh, Coastal title or title adjacent to City Center.
Available earlier with Naval Tradition.
Yield does not change based on the tile's Appeal.
+4 housing, +4 Gold, +4 Science, +4 Culture, +4 Great Works slots, and +1 Amenities. +4 tourism after Cultural Heritage
Acts like Canal.
Gives adjacency bonus as City Center.
What is the Venetian Trade Fort?
1. Venetian Trade Fort is a sort of unique title improvement. You can build neither buildings nor districts in Trade Fort. Trade Fort don't have a population, housing etc.
2. Venetian Trade Fort has one title reach and can not grow. Builders and Military Engineers can improve titles belonging to Trade Post.
3. Venetian Trade Fort can only be built in Coastal title
4. Venetian Trade Fort must be built on neutral territory
5. Loyalty does not affect Venetian Trade Fort.
6. Venetian Trade Fort gives all Faith, Science, Gold, and Culture from titles belonging to Venetian Trade Fort to Your Capital.
It also provides +1 Food and +1 Production to your Capital for every 6 Food and 6 Production from titles belonging to Venetian Trade Fort.
7. Venetian Trade Fort provides all Luxury and Strategic resources from improved titles belonging to the Trade Post.
8. Venetian Trade Fort has Base City strength and Ranged Attack.
9. An enemy can not keep Venetian Trade Fort after conquering it. It will be always razed.
10. You can not assign Governor to Venetian Trade Fort
11. Each Venetian Trade Fort has a unique name.