Krieg is one of the playable characters in Borderlands 2, he is due for release tomorrow in fact. And because I'm so damn hyped about it I thought I'd make a LoL champion out of him.
This is focused on his Hellborn tree where he sets himself on fire a lot. Reference.
He uses his sawblade axe as a melee weapon.
Krieg is manaless, and while he is not exactly a health cost champion in the same way Morde is for example, some of his abilities do damage himself as well. He cannot bring himself below 1 HP through self damage.
Krieg is able to cause a lot of damage in the top lane or in the jungle however he has rather large self damage from using his best abilities.
Multiple DoTs will stack his passive however each will be less effective at this than the last.
If he needs to AoE a creep wave, wait until one gets low then use your W then Q it. It will not only explode to deal damage to the minion wave, it will also apply Fire Fiend's dot to everything too.
Krieg's self DoTs will penetrate 100% of his MR, it WILL however be absorbed by shields like Barrier or Hexdrinker, and be reduced by his passive.
Krieg can refresh the duration of his ult with his E to almost double the duration.
DoTs are counted as damaging debuffs on him, Damaging AoEs which he can just walk out of (Such as Nasus' Spirit Fire) do not count, (unless they also apply a poison/burn debuff to him like Cass' Miasma).
Ignite him early only if you NEED the healing debuff to actually fight him (in which case it's probably better to get Morellonomicon or Executioner's Calling). Ignite him late to finish him off and avoid his passive blocking too much damage.
Don't build Liandry's when facing him...
I had Maya the Siren ready to post too, but Krieg's more relevant right about now because he's coming out tomorrow.