Harry's plan to gain a loyal, loving, companion was on the way. He'd been spending a significant time in the library simply researching things that could potentially be used in the ritual he was going to conduct.
The main factor for him was to make sure whatever he summoned was absolutely loyal to him. He found it almost impossible to trust anyone after his time spent with the Dursley's, so he felt that this was the only real way for him to feel safe and secure.
He knew it was incredibly depressing that he couldn't trust someone without them being soul-bound to not hurting him. But there wasn't really any other way around it... Besides therapy perhaps? But he wasn't going to attempt that for fear of being discovered.
Regardless, he'd found a couple leads on what symbols promoted loyalty. The thing that immediately sprang to mind was National flags... They inspired loyalty in millions, and their primary function was to let known who their loyalty belonged to. Unfortunately, unless he was going to make his own flag, any use of it would likely bend his summons will to the country which owns the flag.
Horses were also apparently regarded as highly loyal, but upon further inspection, they had more links with 'burden', 'endurance', and 'speed'. He didn't want to thrust his burdens upon his summon, nor did he want to take on their burdens himself, so any symbols relating to horses was a no go...
Fortunately, when he realised that animals could also be symbolic, he remembered the most loyal animal of them all... Man's best friend, or, the dog. Dog's had been bred since humans could talk, their evolution guided by humans so they could serve those who they were loyal to better.
Indeed, dogs inspired undying loyalty, love, and companionship. Something Harry desperately wanted. As for how he'd include it in a ritual? That was a tough question to answer.
He'd read that the symbol for hearts meant love and loyalty, so perhaps cutting the heart out of a dog and using that would be the most effective? Though, to maximize the rituals potential he'd need to cut the heart out of a very loyal dog. One couldn't simply butcher a mongrel off of the street... That'd achieve almost the opposite of what you'd want.
Street dogs were isolated and independent, wary of humans. If he used one of their hearts it'd likely poison the ritual and summon something that'd try to harm him. Hmm, he'd definitely need to pick his target carefully.
A day later Harry found himself reading a book in the park, though, his attention was more on the various dogs that were running around with each other, occasionally playing with their owners.
He'd been here for around an hour already, but he'd not yet found a target that suited all his needs... Though, there were a couple with potential.
A Labrador with white fur bounds up to a six-year-old child and deposits a ball at their feet. The child then picks it up and throws it again, the dog sprinting after it with its dangling from its mouth. Harry watched the duo play and eventually decides to act, altering the trajectory of the ball with levitation and allowing it to hit himself in the forehead, dramatically dropping his book and holding his head.
"Ah! I'm so sorry! " the child yells as they run up to him, apologizing profusely.
Harry just rubs his face and shakes his head, "Don't worry about it... It was an accident, right?" the child quickly nods and so Harry continues, "Then it's fine... Nice dog you have there by the way, how old is he?"
"Jason? He's the same age as me! Mum and Dad bought him when I was born, and he's never left my side since!" the child happily says, hugging the dog's neck as it tries to reciprocate with its wet tongue.
Harry smiles, "Is that so?" he mutters, the child never noticing the minuscule edge in his voice.
"Hey, do you want to play with us?" the child asks, and when Harry thinks to refuse he's quickly stopped by his better judgement... The closer he is with the dog, the more powerful the ritual will be.
"Sure."
The duo and dog play for the rest of the day, the child's parents watching from the side and eventually setting up a picnic in the middle of the park. They invite Harry over who refuses, stating that he has to go home soon.
In all honesty, the real reason he refused is for fear that the parents would recognise him from the posters. Regardless, as he's about to leave, the child who he'd not bothered to remember the name of skips over and hands him a bright red apple, "I had fun playing with you, and so did Jason! I hope we can play again sometime!"
Harry nods and walks away, looking at the apple far too closely than one would expect... The reason for this? Apples were supposedly symbols of love and knowledge, and the fact that he'd been given it with friendship? He'd just acquired another powerful ingredient.
He doesn't immediately leave the park however, instead. He waits until his target leaves and follows them home under the Ignore spell. Once he'd located their residence, he marks it down in his memory and finally returns home.
Once back, he sneaks back into the loft and spends a good portion of the night playing Pokemon, all the while still contemplating the incarnation he'd use during the ritual. One thing was for certain, he'd have to conduct it directly at midnight, the most powerful time for sacrificial based rituals.