Still can't fine his weakness even Equip aid Wolf either, if he equip with Dragon heart he's almost unstoppable.
Toxic shaman can usually stop him.
You need TS or Wolf aid on fast attacking hero to counter his healing.
To counter his dodge though, you need high hit rate, especially on your high attack rate heroes, like AD, Ambrosia, SM and dmg dealers, like WT, PG, GS. TS or Wolf aid don't help here, because Heart seems to recover always a % of max hp, which can't be reduced. To increase hit rate you have to either do hit rate enchants, either get your weapons up. Unfortunately even if you max enchant but your weapons will be much lower than enemy wolf's, you will still have problems, so i reccomend you to focus on 5 weapons, including 2-3 brands, and use them on heroes that face wolf.
But even if you counter his dodge and healing, there is still dmg red left. If you don't eliminate it, he will still be as tough to kill as LS after using Taunt. The only things that counter it are Tyrant Brands and Ironclad... And to make Tyrant Brands work you need to make it high purple at least.
If you want to kill Wolvenfiend, you'll want at least -85% hp recovery debuffs on him. This can be done by leveling your TS active from 20->25. Or use an Ambrosia with level 26+ active. There's obviously some other choices, but those are the most popular/best ones.
TS active going from 80% to 85% reduced HP recovery might not look like much, but keep in mind these are percentages we're talking about. Going from 80% to 85% is huge, because that means Wolvenfiend is healing for 25% less than before.
Every Wolvenfiend has a threshold for the amount of damage they can mitigate/heal back up. Once you're (even if only slightly) over that threshold, Wolvenfiends will drop like flies.
Edit: Tyrant's Brand isn't supposed to work on Wolvenfiend. But "only" 80% of his dmg red. cannot be dispelled/ignored, the other 13-15% from talents/enchants/whatever, can be ignored. Meaning he goes from taking only 5-7% (the dmg red. cap is at 93-95%) damage, to taking 20% of the damage. Again this doesn't look like much, but it's percentages again, it nearly quadruples your damage output on the Wolvenfiend. Which of course is 100% useless if you don't have a -hp recovery debuff on him, as he'll just start healing more instead of dying if you don't counter it.