Aegon can’t get fully ramped in act 6. Nick wins because he gets to his full potential so much quicker and aegon doesn’t pass nick until a really high combo.
Nick by a longshot AlsoPhase*
Fully ramped up Aegon is probably the best champion in the game, however, it is hard to actually fully ramp him up in non Labyrinth/Abyss style content. Aegon is by no means bad in act 6 and even at 300 combo, he is pretty solid. Since your question looks like it means fully ramped up Aegon that is why I voted him as he is better than Nick fury at max combo. However, if this was not the intent of the questions, and you wanna know who is better for act 6 content in particular then I believe that Nick fury is better as his max potential is much easier to reach and is thus more practical. You can't go wrong with either choice though both are great champs.