With Kai anyone could trail ride him, he is a great little trail leader, just drop the reins and he will walk and trot on the trail great. But as far as riding him in the arena and making him work, I am the only person who he works for. I was trying to get my mum going on him for when I am away but, didn't work. Kai and I are on the same level, we must have some special connection, I have had him for over 10 years... I think it must be the way I ride, and have trained him too, he was the only horses I was riding for a long while. I don't trust him with other people in the arena but on the trail I would.
Then when Com became mine as well, he used to be my sisters, We clicked pretty well straight from the start, but he is such a different ride to Kai. With my students, it takes at least 2 lessons for them to click with Com. He can be a little moody with people who only "think" they know what they are doing but he is a great teacher. He usually puts riders in their place and builds confidence :) I can trust Com to test his rider, and be a safe mount :) But I also see he appreciates when he has a rider who knows what they are doing.