Ogryn
Up to 5-20% Strength based on the charge time of your heavy attacks. Stacks 3 times.
Hitting an enemy gives them 1-4 stacks of 2.5% Brittleness. Debuff lasts for 5 seconds and can have a maximum of 16 stacks.
20-35% Toughness on Elite Kill.
Target receives 1-4 Stacks of 2.5% Brittleness on direct projectile hit. Debuff lasts for 5 seconds and can have a maximum of 16 stacks.
I probably won't go into as much detail as my Psyker because I'm not a orgyn main but when I do play him I don't struggle even when it's was melee mostly I was just spamming heavy getting toughness back and bleeding and destroying everything and that's the beauty of it and it's very simple (that's why a orgyn can do it)
So you have multiple heavy options I haven't tried all of the but what I have suggested and the knifes are good option the primary should be between the kickback, rumbler and gauntlet the rest are better with different builds you can go full on toughness curios or one health one instead of wound you don't need stamina orgyn has quite a bit.
You entire play through is to heavy attack it's doesn't even need to be a full charge just make sure its a heavy you get a lot of toughness from just doing that your biggest weakness is gunner your team need to focus on them and you best option for them are to charge in and maybe live or rumbler and or the rock but the rock is best to one shot mutants stun bosses when you full charge it but since it recharges it you can be more greedy you want to charge at a horde when there overwhelming you teammates or if your to far away from them and obviously to push bosses back and throw every other enemy on the floor.
As I have said I'm not a orgyn main and haven't used all the weapons on him so please use what you prefer and hopefully you enjoy.
