One of the things I realized when playing the game was that a lot of people ask for how to counter stages/comps, and have no clue how to figure it out by themselves. By chapter 27-28 you should have a very good idea of how to deal with most enemies, but getting there, I never saw a guide on this, so here it is for people who are still early/mid game. You will find that the counters to every hero are almost always the same, what can i say...
Feel free to contribute from your own experience.
Another key is you have to repeat stages multiple times for RNG to be on your side even if it's a counter.
Lucius - fawkes to remove shield, rosa mini-stun interrupts his shield. eironn's abilities go through lucius shield
Estrilda - use brutus or dodge to deal with his charge. also nemora charm works.
Thane - put all your dps on thane's side and hope to kill him quick. brutus / rosa can stall him, CC like nemora and ferael is also good.
Fawkes - use brutus so fawkes will banish him at low hp. rosa also can power up banished carry once she comes out.
Safiya - use athalia or nara to disable her opening shield
Khasos - use fawkes or dodge to escape his opener.
Brutus - fawkes, nara, leave him to the end, one shot him at start so he can't ult during his immunity
Numisu - restart the stage many times, use aoe ult like shem
Warek - same as thane, kill him first or disable him, let him toss brutus
Skreg - kill him first
Arden - mirror arden with your own arden and let arden root him. if he's too fast replace arden boots. if enemy has a lyca, use lyca as well, preferably mirrored as well. nemora on the same side as arden can also charm him. athalia / nara also do the trick
Nemora - use nemora vs nemora or just restart stage until she charms wrongly.
Eironn - put rosa in his suction and she will run away. fawkes can banish him after the first suction. athalia / nara interrupts his vacuum as well
Tasi - use athalia / nara. also a dummy brutus can trick her into banishing him if he gets one shot at the start. use rosa to build energy and ult carry when she comes out of tasi banish
Kaz - brutus
Shemira - she is almost always the most powerful enemy, use fawkes to end her. a faster shemira can also silence her before she silences you. mehira also counters her ult.
Ferael - nemora hard counters him. also athalia/nara to disable him. arden/own ferael are also fine
Kelthur - use rowan / rosa. rowan's stall still stays on your side, rosa runs back. can also use dummy heroes like lyca who don't serve much use after her passive
Nara - own nara / athalia. rosa is also good here to an extent.
Grezhul - RNG. estrilda with SI also kinda works but the hero is meh itself
Thoran - leave him alone until the end
Niru - leave him until the end then CC him with tasi/nemora. low ascension talene works as well
Silvina - use rowan (ultimate insane counter) or put a weak mage in frontline and damage dealer behind, nara also pulls her
Athalia - put rosa against her and rosa runs away. brutus immune stalls her for a while but then she can charge ult up. dodge tank / throwaways like lyca, fawkes are useful too. ferael can also fear athalia nearby.
Ezizh - put 2 dps on his side and kill him fast. i use rosa/belinda so he can't proc his passive
Found on r/AFKArena here.