Garen improvement ideas
Passive (inspired by him using a big broadsword) His attack speed cannot be improved. His basic attacks do more damage (lets say if he would hit 100 he hits 110-125)
Q (this ability isnt really that interesting to use but it could be built upon, also the logic of silencing someone is meh) Same ability but lets say he can activate it again to jump forward a short distance. Charge with him putting his whole body mass into the swing at the end. The blow is so devastating it lowers the targets armor (silence is for the mages, garen doesnt like mages read the lore)
W (greatest ResidentSleeper ability on his kit, he is the most respected member of the Dauntless Vanguard, a Crownguard.. I imagine when he arrives at the battlefield he gives hope to other men who are fighting) I would call it "Demacian Stand", Garen sticks/plants the Demacian banner. All friendly units including minions get inspired - gain movement speed in the area where the banner stands.
- "Last stand" (different ideas they could get lets say 10% hp back or their hp regen is increased)
Demacian Stand can be captured (killed) by the enemy. Garen remembers the name of the one who captured it and seeks to get it back. Garen deals more dmg to the target. Garens team can get the banner back but they dont do more dmg to the target.
Garen can pick up the banner if he is close to it by clicking W again but he cant move for 1s (or so) and the action is canceled if he takes dmg.
The banner recharges hp while garen has it equipped (not placed), so it prevents him picking it up and placing a full hp one down again.
> Garen gained a reputation as a particularly fearsome fighter - one of the greatest in all Demacia, willing to risk life and limb to protect his fellow soldiers and defeat the enemy.
One of the ideas that ive had for his E would be same thing as braums but without the shield so he takes the full damage, maybe also it stops the projectile like 
Q
R - Demacian Justice ( i took the idea from "A twist of fate" video) Garen kneels (1 idea pierce the ground... 2. kneels to "pray"/await the outcome of justice). After a delay a sword appears above the target location (or target) and falls down/slams. If the enemy champion is struck by the sword (centre of the circle) he takes true dmg. The impact is so strong it creates a shock wave damaging and slowing all the enemies. The dmg/slow is higher near the centre/falls down as it expands to the edges This stacks with the W part. Meaning if the enemy champion has previously stolen the banner, the champ takes more dmg
