SMITE

As Bake Kujira, Time Dilate enemy gods for a total of 30 seconds in a single match

This relies entirely upon the use of Bake Kujira's ultimate ability, Yokai's Lament. When used, Bake Kujira will sing for the next 5 seconds, increasing the range of his basic attacks to a large area around him, to a 20 unit radius. In addition, an additional doughnut ring shape will appear from 20 to 50 units around him. Enemies that are in this 20-50 unit doughnut around Bake Kujira are affected by a time-dilation effect. Every 0.25 seconds, they'll gain another stack of time-dilation. 10% slow per stack and a max of 4 stacks.

For this achievement, you simply need to slow down enemy gods using the outer doughnut area of your ultimate to apply time dilation. It's not yet clear whether this stacks when used on multiple gods or not, but as this is over a single match not in one use, it'll be pretty easy.
Worst-case scenario, if you manage to keep one god slowed for the full duration of your ultimate (5 seconds), you'll only need to do that 6 times over a whole match. If it stacks on other gods, you may well be able to get this in one use.

Best attempted in Arena, wait for enemy gods to bunch up and use your ultimate to slow them all down. Repeat this over the match until you hit the 30 seconds required. I'd recommend building cooldown reduction to use your ultimate more often, and protections, to keep close to an enemy god and stay alive.

You need to max out your ultimate before this counts. It also only counts on a single god rather than a group, so to make this easier, choose one target and then whenever your ult is ready for use, find that god, get them in the outer ring and ult them 6 times