Vel'Koz is a combo mage, heavily rewarded for landing multiple spells together to proc his true damage passive

and converting his

to true damage as well.

His abilities are all dodgeable but

is the most important ability to avoid as it sets up his entire combo. Save a mobility spell for it.

Stacking only MR is not effective against him as a lot of his damage is true damage. Health + MR is best.

is the best defense item against him if you're a tank.

is slow to turn which makes it easier to avoid the closer you are to him.

He gains strong potential to 100 - 0 squishies at lvl 6 with

.

is a huge power spike for him.

If he's taking the Glacial Augment keystone, his main spikes comes at the completion of slowing items:

and

.

His ult is a channel and can be interrupted. Cancelling it with a well-timed/saved CC will greatly cut his effectiveness in fights.

He lacks self-peel and

is hard to land at close range, making him a good target for assassins or divers.