Art Design - 9/10 very well done there, only ‘‘bad parts’’ are nitpicks
Ultimate - not a clutch ultimate and thats okay (IB and Ranger have those)
3 Bombs is a VERY good passive and Ranger should have this with healing or potions
10% range power AURA - only gripe I have with this ability that Other auras should be as large
You can actually be playing the game and still be in range of engis arua UNLIKE certain Footknight who you need to hug - so buff FK aura range pls
Cranking - this is a good idea but imho its not fully done yet so its a seemless part of his kit
Problem with cranking in this form is anti synergy
On one hand you need to keep up the stacks and on the other you need to use your other weapons
So my suggestion for Cranking talent changes
1 and 2 Talents will go = Max 4 stacks / No time depletion / NOT lost upon 100% ult charge / 1st talent gives +10% power, Second gives 10% AS / WHEN you start shooting you will loose the stacked pressure BUT for the following 10seconds you KEEP the AS or the Power
So the point is to go for 4 stacks, enjoy the power or AS, take out Ult and for that 10s after 1st shot you still have usefull talents
3rd Talent will be no stacks but direct ult gain per 1 crank - Max 5 cranks - 10% ult charge per crank
This way playing engi is more about enjoying the game and not having to stress over cranking over and over again.
Overheat on siena - esp on unchained comes closest to engis minigame and its much more seemless part of her kit.
Or if you want to keep cranking talents as they are, imho cranking baseline should have some other interaction how to keep it up - like ranged/melee headshots