Mipha may not have been able to win Link's heart, at least as far as we know, but she more than makes up for it in battle as she one of the strongest characters in the game in almost every regard. Although she falls short when compared to Sidon, who is essentially Mipha on steroids, she has a few tricks up her sleeve that elevate her above many other characters.
Despite wielding the Lightscale Trident, a two-handed weapon, Mipha is incredibly fast even before weapon modifiers are added into the equation and is capable of decimating both hordes of Bokoblins and Blight Ganons alike in the blink of an eye.
Playstyle
Mipha, like Sidon, has many similarities to Volga and Ganondorf from Hyrule Warriors, as they all wield a very fast attacking spear or trident with a wide variety of moves in their arsenal. While Sidon is focused on dealing damage, Mipha's focus is on battlefield maneuverability and is one of the most agile characters in the game, both while attacking and while leaping from enemy to enemy through her geysers. These geysers also have the chance to heal Mipha from time to time and she is one of the few characters who can heal herself without using items.
Strong Attack
Mipha's sprinting strong attack will launch her into the air and down onto her enemies, not unlike Daruk's sprinting attack, though Mipha doesn't lose any momentum in the process and can continue on as if she never attacked. While standing or walking, the strong attack will summon a geyser a fair way ahead of Mipha that she can teleport to with her unique action. This is somewhat less useful in continuous battles, though it does have the advantage of getting Mipha to an enemy much faster than if she simply ran towards them.
Special Attack
Mipha's special attack is easily one of the best in the game, as it is not only fast, it is a huge AOE attack that deals damage all around Mipha in a large dome that is almost identical to Urbosa and Riju's special attack. Unlike the two Gerudo, however, Mipha's special attack has an added benefit.
When Mipha's special attack is used, it will also heal her for a small number of hearts at the beginning of the attack and can be a good way of keeping Mipha from dying without using all of her items.
Basic Combo String
Mipha's basic combo string is executed very quickly and has a lot of forward momentum along with it, allowing her to chase down enemies who like to move around the battlefield quickly or think they can outrun the Zora princess. Unfortunately, all of Mipha's attacks in her basic combo don't have much width to their damage and are much better for focusing on single targets rather than large groups, though she makes up for this with her strong combo attacks.
Strong Attack Combos
All of Mipha's strong attack combos summon a geyser in some form or another, with some being more useful than others. Her first and second combo will summon a geyser directly in front of her, making it a good way to get into the air against a larger enemy like Moblins or stronghold bosses. Her third combo, although not readily apparent, summons a spiral force of water that is actually a geyser and deals damage while moving forward, allowing Mipha to jump out of it whenever she wants. Her fourth and fifth combos, unlike her first three, will summon massive spiraling geysers that deal a large amount of damage to anything caught inside its wake while also allowing Mipha to teleport inside them like regular geysers.
Weak Point Drainer
Like most characters, Mipha's second strong attack combo is the best for dealing with weak point gauges, as it deals enough damage to warrant use while also being executed fast enough to be used multiple times in a row. Mipha has another advantage with her second combo, however, as it can be combined with the summoned geyser to execute an aerial combo that also deals considerable damage when used. Mipha's fourth and fifth combos also deal a large amount of damage to weak points gauges, but also sometimes suffer from taking too long to execute.
Sheikah Rune
Mipha's Sheikah Runes don't really stand out among other characters, but they are generally good enough to warrant using both when prompted and in general combat. Her Bombs, in particular, cover a very wide area are good for quickly clearing strongholds.
Stasis can, thankfully, be dodge canceled out of to allow her to use her quick attack speed to its full potential, though her Cryonis and Magnesis Runes are only OK and are best used when prompted against large enemies.
Defending
Mipha's best asset in battle is her agility, so you should be using this to your advantage whenever possible as she moves a fair distance while dodging. However, another way to avoid incoming damage with Mipha is to use her geysers as a get-out-of-jail-free card, since she is immune to damage while teleporting to them as well as being able to get her out of harm's way faster than dodging will.
Weapon Modifiers
The best modifier for Mipha is, by a wide margin, the Midair Attack Damage increase, as this allows her to take full advantage of the launching capabilities of her geysers. Second to this, she benefits from the same seals that most other characters do with Attack Range, Attack Speed, and Normal Attack Damage increases, although she is also one of the few characters who can use Damage at Full Hearts most effectively due to her innate healing abilities.
Unique Action
Using Mipha's unique action will teleport her instantly to a geyser on the battlefield, launching her into the air and, when the post-game upgrade is taken, does a small AOE attack when she emerges. These geysers function similarly to Daruk and Link's Cryonis Rune to launch them into the air, allowing Mipha to not only teleport around the battlefield but also reach floating Wizzrobes or, even better, Hinox eyes or Talus weak points to stun them more efficiently than most other characters.