Bought Define R5 case and Noctua D15.
Suffered from overheating GPU and CPU due to poor case airflow.
Tested out various fan setups and nothing helped.
Said screw it and removed the Nocuta D15, putting my H100i back in as a front intake.
GPU and CPU temps back to normal.
Moral of the story, ClC are more versatile and therefor work better with a larger range of setups. Air coolers are overrated.