I was considering of purchasing a Godox Ad360 to use with my Cactus V6 II to have a powerful flash with HSS. Last week I saw the AD360 II-N (Nikon version) on special, over 25% less than the AD360 (Mark I). So I grab the opportunity and bought one, with fingers crossed that it would work on my K-5. So here's how my tests went.
For those who did not know, you could manually engage the HSS on the AD360 II-N by going into Manual Mode of the flash and pressing the button under the "sync", the HSS icon on the LCD display will turn "ON".

But I found out that when the Cactus V6 II Tx is set to HSS, the AD360 II automatically goes to HSS. To turn it off, you have to switch off the HSS on the Cactus.
Here is my setup:
1. Camera: Pentax K-5
2. Transmitter: Cactus V6 II mounted on camera
3. Flash: Godox AD360 II-N (Nikon version)
4. Receiver: Cactus V6 II at the base of the AD360 II-N
First Test:
Setting on the Cactus Tx:
Camera Profile: Pentax
Flash Profile: Nikon
Setting on the Cactus Rx: Nikon
Setting on the Ad360 II-N: Manual Mode
Result:
- Normal HSS on the Cactus Tx results to banding
- Power sync works (but require adjustment of 10)
- Cactus remote power control don't work
Second Test:
Setting same as above but:
Setting on the Ad360 II-N: i-TTL Mode
Result:
- same as before
I was already accepting that the gear setup will only provide "Power Sync" only and no remote power control thru the Cactus V6 II so I was thinking of buying a Godox trigger until I did a third and fourth test.
On the third test I changed the Flash Profile in the Cactus Tx to "Manual Flash", Normal HSS worked.
On the fourth test I changed the AD360 II-N to i-TTL mode, remote power control thru Cactus V6 II worked. Switching to i-TTL Mode does not provide TTL flash only manual flash so you have to control the power thru the Cactus Tx.
Now I can confirm that HSS works with Godox AD360 II-N, Cactus V6 II and Pentax K-5
Here is the setting that works:
Camera: Pentax K-5 in Manual Mode
Setting on the Cactus Tx:
Camera Profile: Pentax
Flash Profile: Manual
Setting on the Cactus Rx: Nikon ( but automatically switch to Nikon when setting the Tx)
Setting on the Ad360 II-N: i-TTL Mode
Result:
- Normal HSS works up to 1/8000
- Power sync works up to 1/8000
- Cactus remote power control works
I am not an expert on flashes or HSS, but I hope these would be of help to anyone considering of buying a Godox AD360 II-N
Below are some test shots at different shutter speeds, ISO160, 1/32 Flash Power, Normal HSS:

At 1/160

At 1/400

At 1/1000

At 1/2000

At 1/8000