How to fire nukes this fast?

[glass sparrow]

How did this guy do this?

[balmy iron]

Ctrl + left click mirv on a target
Do it too fast to get the same result

[dawn grove]

hold ctrl then left click i guess

[weak mountain]

What does holding CTRL do?

[dawn grove]

nothing alone ,
ctrl + left click opens up the build menu immediately , so hold it while spamming nukes will get you the same result