I’m levelling Ariel to max as my only 5 star healer. She is quite useful in both my defense and attack teams. I have Evelyn as main competition for the emblems(also have triton maxed). My other highly used heroes are Zim, Sartana, Jackal, King Arthur, Kiril, Boldtusk, Caedmon(in tandem with Eve), Marjana and Merlin. Wars and raids are my priority but Titans are important as well. I dont care much about the quests though.
Also have Isarnia at 3-70
Aside from Mother north perhaps, Ariel is the best 5* cleric.
There are some 4* clerics like Rigard ans Hansel that I would prefer leveling over Ariel, since they need less embles, but Ariel is still a top choice.
Asking if Ariel is worth the cleric emblems is like asking if we have to eat to survive.
Congratulations on your hero, you have one of the (if not the) best hero in the game 
3 Likes
Evelyn is not even cleric why do you worry in giving ariel your cleric emblem. And none of the hero you mention are even cleric. . think this is just a way on boasting your heroes?!
My apologies I meant Rigard I am also levelling Eve to boost with ranger emblems as well and I mixed up while writing. My question was whether to level Rigard 5 6 times or level Ariel couple times with the same number of emblems. Fravits answer is quite straightforward though😀