He trusts her.
As a barbarian and a nomad, survival means complete self-reliance. Tryndamere knows this, and has always abided by his single rule: trust no one. His strength came from his rage, his tenacity, and his lust for revenge. And while he was loyal to the people who flocked to him, his trust did not extend to his men. After all, they only followed power. Had he not been as strong, they would cast him aside as a nobody. A barbarian trusts none.
But he trusts her. She, who after years of searching, offers his people and himself a home. She who can be warm, polite, and comforting to politicians and embassies one moment, and a cold, battle hardened warrior the next. Ashe's unpredictability seemed only to draw him closer. After years of being alone, of not sharing so much as a room with another man or woman, her presence is both comforting and foreign. But that's okay with him; after all, who would want boring?
He hadn't always trusted her. When he first saw her, he almost detested her based on principle. She represented everything he wasn't: class, wealth, political power, and culture. She held her head high and carried herself with such authority that Tryndamere nearly bowed to her of his own free will. Hers was the power of money and lineage, of economic brilliance mixed with savvy knowledge of the political world, and it far outweighed the power he could possess with his sword and rage alone.
But she was different from the other nobles and artisans he had met before. He knew how to read people, and often saw true intentions and character through a well-practiced mask. When she spoke, it was sincere. When she asked him questions, she wanted to know the answer. His brusque, matter-of-fact attitude didn't sway her in the least. And, most importantly, she kept her word. She gave him and his people a home.
Their marriage was political for a long time, though thanks to a certain fish that was slowly changing. Years of fighting together on the Fields of Justice, of leading their country, and of simply living together had forged something within him that Tryndamere couldn't quite describe. For the longest time, he knew that he was incapable of love, of intimacy. It had been yanked from him the day his family was murdered. But slowly, surely, she was beginning to prove him wrong. Not yet, but someday. Someday, he could love.
A barbarian is completely self-reliant, and a warrior knows that the only one you can count on to have your back is yourself. There is no room for error, and there is no need to trust anybody.
He trusts her with his life.
She loves him.
As a politician, she knows the game. You talk with the embassies, verbally dancing around issues and schemes until you reach an unspoken agreement. There are bribes, there are alliances, and there are marriages. Each is simply a tool used in the gathering of political power. The strain consumes her life, leaving almost no time for personal matters. The thought of a family, of affection or a relationship with anybody is farfetched; with someone in her political world, unthinkable. A politician doesn't become attached, doesn't love.
And yet, she loves him. His loud mannerisms, quieter and more reserved after years of practice and discipline, still stands in stark contrast to the rest of the nobility, and he is most likely the best behaved barbarian at that. And though a lifetime of conditioning allows her to maintain a stoic and straight face, her willpower to suppress a grin is tested when her husband blatantly asks a council representative "why the hell you have an outdoor fountain if you can't wash in it? It's a waste of perfectly good water!" Or how he will demand, from time to time, to cook his own food, which results in a messy kitchen, very angry cooking servants, and the most rudimentary-made meal ever served within the castle (though the food is excellent, and better than anything the servants could make, she will admit).
Her love was hard won; like many hence, their first encounter was less than ideal. The warrior, the barbarian, marched upon her lands with an army that could cast fear into the hearts of the most hardened Noxian generals. The barbarians had been known to wave the flag of peace until the city dropped its gate, and then attack without mercy. So when she greeted him, it was with as much authority and intimidation as she could muster. She chose her best clothes, took her finest royal guard, and even had a large part of her army escort her to the waiting barbarian leader. She had hoped for fear, intimidation, even a look of surprise. But Tryndamere had simply glanced at the show, grunted, then strode forward and greeted her as his equal. Her entourage had been appalled at his lack of respect, but Ashe couldn't help but feel admiration. She returned his gesture, refusing to treat him inferior during all of their talks. And his cold, brutal honesty was refreshing to her mind. After years of playing the political games, she was able to talk openly and straight. And she loved him for it.
It was a long time after that before their relationship grew past the political. It had taken a threat on his life, as well as some helpful advice from Fizz, for her once again break the political lens she had viewed him through. She saw once again the man she had originally seen; the handsome, rugged, honest man, who threw political correctness to the wind and treated the wealthy duke the same as the lowly pauper. And when she saw him happily playing with the young children his people and, slowly, her people brought him, she found herself falling in love with him all over again.
It's the little things that remind her now. The under-his-breath cursing as he attempts to make sense of another Yordle's contraption, his look of pure confusion whenever he sees four spoons and three forks at a formal dinner ("But why so many? Are they so pompous that their silver wear demands their own course? Is the salad fork too important to be bothered with steak?"), or the way he'll unconsciously wrap his arm around her while they sleep. They all make her smile, and remind her again that she loves him.
A politician is distant and removed. They do what they must for the good of their people, and do not dwell in the personal. A politician does not love.
She loves him.