So....there are 21 Epics in the game, which is as same as amount of the Rare cards in game. Here i'm going to rank them from worst to best.
PLEASE NOTE, THIS IS JUST MY OPINION!!!
Clone is just plain bad. Clone is very expensive for its value, and all of its good counters (Tornado, Poison, pretty much any splash) are very popular cards. It just doesn't work in almost every deck. Only in Golem and Lava Hound decks it works well.
I have a hard time deciding either this or Clone should be in the last place, but this is slightly better IMO. Mirror can copy very powerful cards like Battle Ram after you baited out their hard counters, but if they have other counters. You're just putting yourself in Elixir disadvantage.
Although they have spell resistant shield, that doesn't make them good enough in defense. It's because of their weak DPS, and how hard to level them up since they are an Epic card.
Tough to master, this card takes high skill to use efficiently, it costed heavy 6 Elixir and it can be distracted easily by high-hitpoint troops. But if it locks to your Arena Tower....
17. Giant Skeleton
This card is useless on offense, you are lucky enough if you can get it to the tower. That's why this is better on defense, but still i think this quite sucks.
Good cheap support spell, but the fact that it only give 0.5 second increase each upgrade, there is no point to upgrade it. And the spell can be used indirectly via Lumberjack. But still not a bad card at all, it is less risky than Clone.
Risky and expensive, but if used right can be very rewarding. Very good on clan battles. This spell is the best friend of Balloon and Hog Rider.
When it loses the slowing capability, it get kicked out from the meta, and was one of the worst spell in the game. But the buff that makes it kill Skeletons in 1 tick (Since Graveyard is kinda popular) revived this dead spell. Now it is good for suprise, but Fireball sometimes do a better job in most situations.
Sorry GLeen...But i think Prince isn't that great, especially with popular Electro Wizard around. It can be countered easily, but can crush towers in seconds if he somehow manages to get there.
12. Dark Prince
Nice support card, i think this is better than Prince since he has more capabilities. He has the best sound effect of any troops, can counter troops like Bowler, mini-tanks, glass cannons pretty well. But he still doesn't have enough damage and radius, increasing both of them will be the best buff to him.
This spell kinda sucks in most decks. It costs 6 Elixir and can target only 3. But if used with right decks, gosh, this is so powerful. I don't really know if this needs buff, nerf, or both.
10. Goblin Barrel
Very powerful, for 3 Elixir they can damage a lot. But still, there are many counters which makes it kinda difficult to use. But if used correctly, they can take down a tower.
Witch is very powerful due to the most recent buff. She is great on defense and support, her Skeletons are perfect for distraction, but the Witch deals too low damage, making her ineffective against air pushes. She also quite fragile.
8. Skeleton Army
Very unreliable. All of its counters are very popular cards, i didn't see many of them in Hog Mountain. But for 3 Elixir they can counter everything, but still, they are very unreliable, and literally useless on counter push and offense.
A really good card on defense, i totally underrated her. She can translate to a deadly counter-push. She is one of the best anti-cancer cards. Powerful against any tanks, can devastate tower with my supports. But she is quite mediocre now, let her have more damage and health. But succumbs to Inferno Tower :(
6. Baby Dragon
In my opinion, it isn't that great. Sure a flying mini-tank that deals area damage is insane. But its hitspeed is too slow, making it quite ineffective in some situations, but it pairs well with Golem and Lava Hound.
Bowler is OP on defense. His knock-back is useful against medium troops. He has high health that can be used to tank your troops. He is also good on counter push.
One of the best building damaging card. Extremely powerful bomb and has quite a lot of health. Supported with many troops (Tank + spell), good luck defending your tower.
I love this card. Pulling enemy's troops to King's Tower. Pull troops to the center to allow spells or splash damage hit them all at once. Sweep enemy's troops to the other lane. Works well against swarms too. Really really great spell.
The best tank in the game. Costs heavy 8 Elixir, but it was totally worth it. It has tons of hitpoints, even if it is weak to swarms and high damage troops. You can support it with many troops and spells. And GG!
Suprised? Executioner is the best splash troop ever! He is so OP when released, but now he is quite balanced. He can damage glass cannons behind a tank. Absolute beast with Tornado and P.E.K.K.A. And has high health to survive even Lightning! I like this card a lot.