In your last essay you wrote: “But an important point regarding Stannis as a tragic figure: in tragedies, the tragic hero usually accomplishes something in the process of their downfall.” Cersei is a tragic hero whose situation is very similar to that of Oedipus,’ a woman whose attempts to fight fate actively bring it about (let’s not split hairs about her being a hero, the Greek heroes were often ruthless, dishonest, impious, and murderous). So what will she accomplish before her downfall?

Well, let me count the ways:

1. Becomes Queen. 
2. Kills Robert.
3. Supplants his line on the Iron Throne.
4. Overthrows Ned Stark. 
5. Gets Tyrion convicted of treason.
6. Takes over the royal government. 
7. Gets Margaery thrown in prison.
8. Seemingly does it a second time after her Walk of Shame, given what we learn in “Mercy.”

She’s not triumphing over her destiny – Joffrey’s dead, Myrcella is probably dead (slow-acting poison on Darkstar’s blade, mebbe), Tommen’s def. going to die – and she has had some huge setbacks (Margaery getting bail, getting thrown in jail, Walk of Shame) but she’s accomplishing things in the process. 

In the future, there’s a bunch of stuff she might accomplish, anything up to burning the entire capitol to the ground.