Slow build-up and discharge LED effect
Drawing the schematic in the conventional way will generally make it more clear what's going on.


Voltage decreased from the top of the schematic to the bottom. That way current flows from top to bottom.
Circuit reads from left to right. In your case C1 controls the rest of the circuit so it makes sense to put that on the left.
Draw transistors the "right way" up.
Use GND symbols rather than earth as the earth symbol implies a connection to mains earth (and the planet Earth) which probably isn't what you intend in this case.
GND symbols should point to the ground. Never sideways or upwards.
Your battery symbol has no connection on the right. It should be connected to GND.








simulate this circuit &ndash; Schematic created using CircuitLab

Figure 1. The OP's schematic redrawn.

Now it becomes clear that each transistor's base voltage reduces by the base-emitter voltage drop of the previous transistor. This will be a 0.7 V drop per stage.

I can't see an easy way to do what you want with this approach.