I would say, you should start working on Gregorion, he is a decent 5 * green hero. In this game waiting for a specific hero is like waiting more than a year… so my advice is, work with what you have at this moment, besides getting a 5 * hero to the max takes time, maybe in between you got more options but do not stop and wait for something uncertain…
Zeline and Alberich could be months away with the tiniest chance to summon them even with exorbitant spending. Ive learned to not set myself back from further progression waiting for that ‘perfect’ hero when you’ve got a good option already. Greg is a good 5*, similar to Lianna, although geared more towards Titans.
Bring him to 70, if you happen to get Alby/Zeline before you get your last ascension items, then switch priority. Greg would still be useful at 70 for his crit utility and elemental link on blue Titans. If you don’t get Alby/Zeline before you get your last needed mats, ascend Greg with confidence.
I didnt even mention Melandor because 5 tonics is the right number to be making 5* plans, saving your sturdy shields.
I would say level Greg. He’s a solid hero. Also, a bird in the hand is worth more than 2 in the bush. As mentioned, level the hero you have and not the hypothetical one you, may, get. I’ve been using Greg and his criticals are amazing.
Start on greg. Sometimes shield can be a pain and by the time you get the sixth tonic, you dont want to wait for 6 more shield because you spent 4 of them on a 4s. Also greg is solid, you wont regret spending mats on him, at least I love my greg.
I don’t have 2 gregs XD…I am also mainly focused on titans and events. I forgot to say that I have all the mats for a 5* red hero, but I didn’t get any yet T.T