Soon, the invaders arrived on earth and the war began in full.
Perhaps, the most disorientating thing was the fact that the invaders looked just like humans with absolutely no difference. There were some that had different and unnatural skin colours and quirks, but that was the most of it.
Those that invaded couldn't really be referred to as aliens,
He gets exp, but it doesn't add automatically. He has to allow the system to use the exp to level up before it can. Later on, he unlocks a system feature which gives him the option to select seven creatures(could be people or whatever.) These seven, he can customize through the system and give them things like abilities if the person has a slot, and also share some exp with them, though there's a limit.