Dragon Ball Super : Destruction

On beerus planet trunks training started .....

Whis: So trunks first i want to know how strong you are in present so go on and power up to maximum.

Trunks: OK, but i reached a power level during fight with zamasu and i don't know what it was can you pls explain

Whis : Most likely it wasn't any new transformation you were starting to using your life force without knowing it somehow it was like goku's kaiken but different so just power up to maximum..

Trunks: yes

Whis:There will be three things which we will work before god ki so first just hold this max power as long as you can

Trunks:(after 3hours) how long do i have to hold this my power is slipping

Whis: just hold it until you you can't even stand (and after 5 hrs trunks almost back to base form)..so you lack stamina

Trunks: (completely lost nothing remains ) i wonder how goku and gohan holded their super saiyan form for days

Whis:oh so goku did train like this too so how long he holded his super saiyan form

Trunks: almost 10 days

Whis: he must have trained hard for it as you know you saiyans are race who transformed to hold greater power and emotions affect it too and you mostly live in your base form so strain on your body is too much when transformed but when get used to it strain reduced and it is directly depend on your base form how much strong you are in base form more likely strain will be less when transformed.... so second to check how tough you are in base form

Trunks:right now i am completely exhausted (whis healed him) ok now i am good to go

Whis uses hia staff and just a little tap trunks got hurt badly which shows his body is not tough enough to power like god ki

Whis: ok so we have to work on toughness too now third speed(after some test trunks is not as bad whis thought) so you are fast but still compaire to lord beerus you still look like a turtle but we will work on that too so now we will work one by one

For stamina whis set target for trunks to use his maximum power for 1 day (no fighting just daily work) noe trunks train for 2 months like this now he can hold his full poer for three days

Trunks : oh so now i can hold full power as ssj2 for three days what next whis

Whis:now you fight me and use your max power and try to kill me

Trunks: ok so mean really ,you got it

after 1 hr at full strength trunks completely exhausted

Trunks:what only one hour i know fighting will decrease time but this much

Whis: so now you know so what to work on

trunks now train so he can fight a day at his max power all the time which sound easy but it took trunks 6 month to reach it

now for endurance

Whis beat him to the pulp every time and then let him heal naturally this goes for year too which they decide to train in hyperbolic time chamber where 1 day is equivalent to a month so trunks train for 1 year inside(12 days outside) now trunks can take beating from whis and not passed out

Whis: One thing i noticed that i wanted train so your body can move on it's own but you also have problem like vegeta tight nerve and stressed

Trunks: Howw you know about my father you never trained him

Whis : Oh I just asked everything about those two saiyans and he said goku have more chance to master this technique he evr will but vegeta is too stressed for that so you have to learn more