How to dual mine Loki and Turtle coins
What is it? Is it legit? I know coin developers was trying to avoid merge mining in the past ...
It is, it's working. You mine 2 coins at the same time with the same hashrate

It's not a new concept either.
I used to merge-mine CN coins back in 2014.
Unfortunately they used to be shitcoins mostly, but now there seems to be a resurgence. TRTL+LOKI is good, but there's a whole bunch of others (XHV+BLOC etc).
You can head over to semipool and check. They've got quite a few combos on offer.