Champion Concept: Kalazin, the Dragon's Justice

This is my first Champion concept, so I decided not to add the stats since I wasn't accustomed to creating Champions.

Lore

Kalazin felt the heat of the dragon's breath wash over him, his skin prickling and stinging with the heat. Despite his constant salvos, the dragon seemed not the slightest bit wounded or perturbed.

This was a bounty he should have never taken.

The dragon was becoming more and more ferocious, now making deft swipes at his legs and body, a few coming close to hitting. One swipe connected cleanly with his side, throwing him sideways into the stone walls of the cavern. He felt the warm sting of blood dripping down the side of his face, but he was far from defeated. Kalazin the Kingslayer, Kalazin the Trueshot, would not give up so easily. He was determined to add Kalazin the Dragonslayer as one of his many titles.

The dragon approached him, breathing in to release a burst of flame, but Kalazin was ready. He rolled out of the way, catching the dragon off guard as he rounded it, firing a single, powerful shot. The shot flew true, nestling itself deep between two of the dragon's hard scales. It let out a blood-curdling scream, angry smoke streaming from it's nostrils. Kalazin took this moment of weakness, and capitalized. He threw out his clawed lasso, sweeping it around the dragon's neck and pulling. The dragon resisted, but in it's state of duress, it could barely challenge Kalazin's strength.

The dragon opened it's mouth to release a burst of flame, and Kalazin smiled. He raised his revolver, and fired five shots straight down the dragon's throat. It did not have time to screech, as it feel to the ground dead. Kalazin chuckled, and then his smile turned curious. Something had rolled out of the dragon's mouth. A glowing orb? He'd never heard of such a thing, but he guess some pompous king would buy it for a good price. Kalazin hastily reached down, his hand feeling a gentle heat radiating off.

His hand closed around it, and the last thing he saw was a vision, a vision so terrible, so cruel. The old Kalazin never did wake up.

Abilities

Passive: Infused Rounds

Kalazin's basic attacks and Quinsalvo passively stack Infused Rounds. After 3 stacks of Infused Rounds has been applied, the enemy gains 1 stack of Growing Flame. Each stack Growing flame deals 5-20 (based on level) (+10% AD) physical damage per second for 3 seconds. Growing Flame can stack up to 20 times, and each stack will increase the damage of every other stack by 10%. Stacks are refreshed by basic attacks or Quinsalvo.

Q: Quinsalvo

Kalazin, over 0.5 seconds, fires 5 rounds in an arc. Kalazin can move during the duration, but is slowed by 10%. Each round deals 20/40/60/80/100 (+30/40/50/60/70% AD) physical damage, and slows the target by 25%. Enemies can not take damage from multiple rounds.

Mana Cost: 40/45/50/55/60 Cooldown: 7 Seconds Range: 750 Units

W: Bladed Lasso

Kalazin begins channeling, for up to 2 seconds. Over the duration, the range of Bladed Lasso increases. Bladed Lasso stops at the first champion or epic monster, dealing 40/70/100/130/160 (+60% Bonus AD) physical damage, and tethering to them. While tethered, you do 5%/10%/15%/20%/25% bonus damage to the target and slow them by 30%. Tether breaks after 4 seconds or after the travel more than 1500 units from you.

Mana Cost: 80 Cooldown: 20/19/18/17/16 Seconds Range: 750/1350 (based on channel time) Units

E: Fed By Flames

Passive: Per stack of Growing Flame active on enemies, Kalazin heals for 2/4/6/8/10 (+2.5% AD) per second and gains, 1%/1.5%/2%/2.5%/3% move speed. Healing is reduced by 50% on non-champions.

Active: Kalazin ignites, dousing all stacks of Growing Flame on enemies but gaining 3%/4.5%/6%/7.5%/9% move speed per stack doused. This speed boost lasts 3 seconds.

R: Might of the Dragon

Kalazin draws power from the orb, calling forth a spirit dragon to set a conical area aflame. The initial flame deals 100/175/250 (+60% Bonus AD) physical damage, and then the fiery area does 50/87.5/125 (+30% Bonus AD) per second. The area lasts 3 seconds, and grounds enemies inside it.

Mana Cost: 100 Cooldown: 120/100/80 Range: 800 (can be cast anywhere this far away), 750 (length of cone)

That's it, I hope you think this concept is cool! I'll bet that it's probably unbalanced, but I'm not experienced enough to tell. Tell me what should be changed to either make the kit better or to make it more balanced, or just flat out tell me it's too similar to other ADCs.