Ok. They must have changed Guardian Angel because I remember being able do that trick. Thank you though, don't want to look dumb by giving tips that don't work xD. It's not that the junglers I listed are the ONLY ones that you shouldn't try to counter jungle it's that those were just some examples. Also about Nasus, I find that he is a very strong jungler in the aspects that (A) if he/she knows what they are doing, (and with the new jungle route, not going straight to red), then they will have already picked up quite a few stacks for that early damage and (B) with his Soul Eater giving him that natural sustain he is generally at 3/4 to full health when he gets to red. (C) Also, I don't know about everyone else but when I take Nasus in the jungle I like to take my time and do a full clear before ganking, so I'm not sure the invade at red early would even be worth the time. Thank you for your feedback though, much appreciated. I'll remove that Guardian Angel thing soon, thanks for pointing that out.

Hi, seems like a pretty good guide, nothing wrong with your build, but i have a few little things to say. First off, selling and re-buying a GA does not (unless it was changed for preseason) reset the cooldown. You can however sell it and buy something lese for while the cooldown lasts.
Second, there are a number of junglers, aside from those you mentioned, that can defeinitely not be invaded at red. Off the top of my head that ***uld be definitely Udyr and also Shyvana, and maybe master Yi. Aside from the fact they might already be clearing red when you come there because of their fast clear, they also do insane amounts of damage early, and Udyr has the added problem of not getting that low in the jungle. Honestly any tanky jungler with fast clear will be a problem for you to invade. Also i see no problem in invading a nasus earlygame, as long as you make sure to kill him before his wither comes into effect or bait him into the bush where your JitB's are.
Just my 2 cents.