An easy way to tame him once you are into late-game and have a Tek chestplate.

-a good amount of Bio toxin.

-try avoiding Pump shotguns and rather go for a fabricated sniper rifle. (The rifle does damage in per bullet which makes it easier to control the situation)

-a tek chestplate.

So basically you just hover over him and tick away his health until he goes into a defensive stance. Tick away some more and he SOMETIMES does his adrenaline roar. Not to be mistaken with his health restoration roar. Once he does his roar you need to dive bomb him by disabling your chestplate and spamming the feeding button. And basically rinse and repeat!

And if somehow you screw up and do his health too low you can lead him to weak creatures, he will eat them and restore about 50% of his health which grants you a second chance!