So here's the thing about Matin's writing:
Several of the (significant) plot-devices he uses... he uses TWICE.
Once on a small Scale.. and Again on a GRAND scale.
Consider this:
Daenerys' fire birth- Khal Drago funeral (season 1) & Burning down All the Khals (season 6)
Trial by Combat- Tyrion's trial (season 1) & The Mountain vs the Viper (season 4)
Greek-fire- Battle at Blackwater (season 2) & Cersei brings Down the House (season 6 finale)
So, if you have been paying attention....
then you should be expecting one more re-occurrence:
Kingslayer slays his King.
*mic drop*