Let’s make a ‘‘comprehensive run down’’.
I have been focussing myself on building a versatile bench of 4* heroes after my bench of 3* heroes was ‘‘complete’’. I don’t think it’s necessary to have such a 3* hero bench, but I would strongly recommend you to do so with 4* heroes. Unless your 5* heroes are key heroes and game changing, you can make your life easier with 4* heroes regarding the amount of rare ascension materials spent and earned.
In all honesty I would leave Cyprian at 3/60 and bring Tiburtus to 4/70 instead. His special skill will be a greater asset to your current team in any part of the game, where Cyprian will only be useful occasionally.
After Tibs, I would recommend you to work on Rigard for the reasons @JonahTheBard gave you. I think he meant ‘‘Victor’’ instead of “Vlad”, because Vlad does not require Trap Tools to level up of course. Victor clearly is a nice hero, but I would rather level up Rigard first. Just as Tibs, Rigard is of more use in any situation.
You’re on the right path. Chao next.
Boldtusk indeed. After that, it depends, I guess. According to my own principles I would go for Gormek after that. He’s a red Tiburtus, but more tanky, so review the explanation above. Zimkitha her special is useful, but Boldtusk his attack boost is stronger. Also, Rigard will remove status ailments of your allies as well. I do have Colen and Kelile myself and still use them, but Gormek his special is more useful.
My 4* order would be: Boldtusk - Gormek - Kelile - Colen
Kiril indeed. Based on my suggestions you would have Tiburtus and Gormek soon in order to decrease the defense of your opponents. Grimm is the third with that ability, but since Sonya is already at 3/60 I would finish her first after Kiril.
My order: Kiril - Sonya - Grimm - Boril
Melendor indeed, but with Kiril/Boldtusk and soon Rigard a case could be made for Caedmon. Anyway I would also favor Melendor first, so that you will have a hero who dispels buffs from your opponent. As you lack hitters, Caedmon would be my next choice.
Kashrek is a great 4* tank. But, to me, that’s it. Since you already have BT, Kiril, Melendor and Rigard there’s no need for his healing ability. He would be the last one I would choose to level up, also if you happen to receive another 4* or 5* green hero.
My order: Melendor - Caedmon - Kashrek
As for your 5* heroes, I do not believe that any of the ones in your possession will change your game significantly regarding their special skills. Your 4* heroes will do the same job, where some of them do so combined.
Victor can however be a great choice, but I’d recommend you to read other threads about him.
3* heroes I would use to finish the rare events: Balthazar, Berden, Brienne(maybe), Nashgar, Azar, Tyrum, Valen, Kailani(maybe, last levels), Bane, Belith and Hawkmoon.