Strong Heart didn't have any obvious transition to being brought to a home with two other cats. He wasn't bothered at all by them, he simply seemed overjoyed to be home.
Light Heart and Golden Heart participated in the obligatory hissing that any respectable cat would do when faced with an introduction. Strong Heart didn't seem to notice.
I remember well his first day integrated in to the family after a brief period of separation. He would sleep on my chest as I lay on the sofa, only to wake from time to time, LEAP off me to the floor (he never carefully climbed down - he always bounded everywhere he went), played like mad with some toy until he was exhausted, and them climbed back up on my chest to sleep again - always sleeping on me.
To this day, I don't think I have seen a living being express such joy as he did in those early days, when he knew he had found his way home.