this is to scale on my sona's estimated size. it is possible to say Death is roughly 20ft tall in beast mode but the scaling is to serve based on my human height (guessing 5 1/2 ft)

now to know how Death goes from being a small fry to raging behemoth?

first and for most its where he's having a bad day with something he just wants to enjoy and if its person or thing, if it grinds his gears to the point of no return he'll let you know by wanting to throw something or simply yelling in anger, which will soon trigger the transformation

another is if he feels threaten and realizes its no more mister nice guy, if he is overwhelmed by taunts or another's feeling for dominance over him then he'll sure enough start to feel its time to release the beast