Overview
Yve is a Mage who can easily control the battle with her skills.
Strengths
In Laning, Yve can fast clear the minion wave due to her spammable First Skill. Her Ultimate can control the battle with it's range, crowd control, and damage while staying protected in the backlane. Her Poking capabilities is one of the best and can easily dominate her lane from Early to Late Game. Yve's Passive also provides her with shield and speed that can help with surviving and running away from enemies.
Weaknesses
Like every hero, Yve also has a few weakness, One of which is that she has no blink skill which is important in survival and chasing enemies. Her Ultimate also makes her unable to move from the spot, making her a target in team fight and relying on teammates to protect her.
Spam 1st Skill
Demon Boots can provide the Mana Regen that Yve needs for her spammable First Skill. Glowing Wand is A MUST, Useful for Team fights especially if the enemy uses Spell Vamp, Lifesteal, or has a support teammate that can Heal. Blood Wings for the Shield and Movement Speed it provides, crucial for survivability. Holy Crystal can vastly increase her Damage, Making her Poking Capabilities easier. Winter Crown (interchangeable with Immortality) for Survivability. Queen's Wings provides her with Spell Vamp, HP, and it's passive "Demonize" which is useful for Survivability. Cooldown Reduction may not significantly benefit her damage source (First Skill) but it can help reduce the cooldown of her 2nd and Ultimate Skill that can be used for Zoning the Enemy Team. Adaptive Attack and Passive "Defiance" for extra damage.
Damage + Rotation
As a Mage, The Mage Emblem is the best choice for her. As for Emblem Talents, Rupture or Agility can be useful for her as Rupture can provide extra Penetration while Agility provides extra mobility for her, Wilderness for faster rotation and is helpful for team fights when contesting with objectives like the Turtle or The Lord. Lastly, Impure Rage is the best pick for her as this talent provides extra damage with skills and can recover her mana.
Battle Spell
Flicker suits her the best as with this battle spell, she can be rid of her No-Blink Skill Weakness. Another Option would be Purify and is mostly used when the enemy has a lot of crowd control skills.
Early to Late Game
When using Yve, it is important to maximize her Passive as this can be helpful for survivability. Her 2nd Skill and Passive can help identify whether the enemies are hiding in a bush. Just like any other heroes, Yve has counters. As a Mage with very low mobility, Assassin Heroes are her worst enemies, Their mobility can make easily make Yve miss her skill and not activate her passive—making her a squishy target. Another Good Counter would be Artillery Heroes like Novaria and Pharsa as their Long Range Skills would be a nuisance for dominating her lane, with Artillery Mage, They can avoid getting poked by Yve and still fast clear the lane while maintaining a good distance.
Best With Fredrinn
100% co-op win rate
Tanky Frontline Heroes with Crowd Control is the Perfect Match for her as she needs a teammate that can be in the Frontline and crowd control the enemies in place for her to do High Damage.
Watch Out For Kadita
40% counter win rate
With Kadita as the enemy, Yve has the risk of Kadita's burst even within the backline as Kadita's First Skill can ignore any control skills making her a counter for Yve.