1) Unlock event's :
A) When x city has be taked by x player for certain turns:
" After the capture of moscow, the russians repel to siberia, starting a new capital over there".
- New capital: Yelakenburg.
- Some russians's troop event.
2) Unlock event's: When player general has survived until x turn:
"Yoshimoto manage to escape from his brother. After his escape, he organized a strong army..."
- Japanese Yoshimoto get troop event.
3) Unlock event's: evolve unit's (already suggested).
4) Unlock event's: Add % to country income
For example, turn 5: " After the winter, the russian mechant manage to recolect more income" + 20% russian economy.
Would theses suff be hard to implement?