One of the saddest season finales I've watched in recent times.
Chuck was a character that wanted to do things right, no matter how skewed his views might be and how affected by his brother he was. Seeing a mentally ill person who always tried to keep things in order and was actually working into recognizing his condition and getting better to break down in loneliness like that, completely give up after destroying his own home and resort to suicide by fire is profoundly upsetting. Kudos to the show for managing to make me feel like this without resorting to cheap tricks. In lesser hands, such a development could have been hokey.
The opinion a brother holds of you is a powerful thing. Congratulations to the writers for using it as a driving force through these seasons the way they did. I'll miss Michael McKean on the show, he always added a lot into making BCS what it is.
If there's anything to look forward is how this will hit Jimmy. Even if he doesn't know it was a suicide, he saw Chuck in his final moments while the house was intact, the lights were on and music was playing, so he'll likely know something went wrong. As much as Chuck helped congealing the worst of Jimmy into "Saul", Jimmy also had a hand into ultimately breaking Chuck with the shaming in court and the rising of the premiums, which was the catalyst for his final situation with Howard at HHM. Inadvertently or not, one brother kept hurting the other until the end. Like they keep saying on the podcast, BCS truly is a tragedy.