It's tempting to go Aegon first, but unless you have a stacked roster of r4's, and you're deep into content, Aegon isn't going to be beneficial for you outside Abyss, LoL, and other longer content. Base your decision on what you need to accomplish now - Still struggling in AW/AQ? Haven't gotten through Act 6.1 and 6.2? Still haven't completed a 100% run in Act 5? With the exception of Sentinel, I had the same champ options as you, and went Sunspot first. Zero regrets - he made getting through everything else easier, and I was able to rank Aegon, Void and Warlock faster because of it.