I've only had one or two negative trips, the first one was when I found myself talking to seven pillars of blue flame (nothing in this world existed at all. I was comfortable. My tripping buddy thought in was having a bad trip and kept shaking me, the shaking caused my trip to spiral down, because the blue flames were really important for some reason and the 3-4 separate times I was shaken and brought back here to this world, it made me sad more than anything I was not scared.
I tripped on lsd and took some crystal speed or something from a Mexican buddy of mine. When I snorted the crystals all my lsd visuals turned, I guess what other people might consider dark and scary. I saw what people would consider deamon and dragon faces and corpses and sharp hands/claws with knives, all sorts of things. It went on for at least 3 hours. I called a friend and told him I was tripping and needed some help come quick I'll give you weed. When he came I told him what was going on, and just said the visuals were dark (not scary) I never felt fear or was scared of them, I just saw that it was something my mind was manifesting on top of the lsd visuals, I even tried to interact with the hands and full on deamon bodies, which was very amusing to my friend.
If you look at something and label it (Satan, demon, devil, fear, anger, rage, horror) then of course it will be associated like that. I SAW the face of "Satan" but to ME there is no such person/being as Satan, its all a facet of your mind, which I refused to let it propel me down a dark path. I instead greeted the negative imagery with open arms and told it that it had no control over me whatsoever, but that it was INTERESTING to me, so please continue showing me yourself.
One final negative trip I had, I tripped on 4aco dmt, and right when it hit me, it just kept building. And building. And building. "I" was no longer in control, so "I" told it to come take me, take me over completely but first, let this body that used to be "mike" get into a comfortable position. The 4aco dmt did just that. It understood that what was going on was a little more (OK a shit ton more) than I expected, and it felt like it GAVE me permission to lay down. It literally calmed down for about 2-3 minutes, I lay down and heard a voice say
"We hope you are ready because we will not take it easy"
And I said
There's nothing I can do, so come at me and help me learn