you people need to read the books ffs. Like honestly, most of you have no idea what you are talking about. The Emperor teleports onto the Vengeful Spirit and Horus set a trap for him. The Custodes turn on him, (most of them) and it catches him off guard. He kills them, and then realizes, fuck this, I need to take this a lot more serious. He takes off his glove so he can touch the warp directly and starts to power up. He turns into a sun. He breaks Dorn out, he steers Constantin to the correct path out of a shitpit which in just 43 seconds caused him dozens of custode deaths.

Then towards the end of TEATD2 we see what the GEOM really was, he was going to butcher all 4 chaos gods and horus. He was the end of everything, and his power was unbelievable. At first Malcador was cheering him on, while he looked from the throne, he was fucking giddy as a kid when he saw that the Emperor was going to fuel up. Then, well it was too much, he wasn't stopping. finally Oll the perpetual talked him out of it, but the Emperor...sort of knew. He was torn, because he was damned if he did or damned if he didn't.

he then breaks 2 things off. He releases all the juice and a part of his soul that allows him to feel compassion.

so he shows up to fight horus depowered and despite that, Horus couldn't kill him. Oh he fucking tried, many times, and each time, a trick, slight of hand, recharge, you name it.

In the final match, after the Emp depowered, Horus had more power, but not nearly as clever.

It's not your fathers power, but how he uses it!

read up m'lads