Vrask is an okay healer, and I did personally level him to 60 - but only for faction wars. I wouldn't recommend investing any more resources into him for now. You won't have wasted them, but he won't really help you much right now.

The three champs you have at 60 form a decent core. The two pieces you're missing are poisons and crowd control. Unfortunately none of your champs are really *great* at that.

I think for now I would just focus on leveling food, but if you're really itching for someone to bring up next, your safest bet is probably Coldheart. She's on many endgame teams - she just won't really do a huge amount for you yet.

As for Ronda - she's good, no question, but without lego books her value is significantly reduced. I wouldn't invest in her yet, but she may very well end up being the person you book, depending on who else you get.

Would make more food or go with Ronda. She'll help us wave clear in Dungeons faster. 

One other option when we build out a clan boss team could be Coffin Smasher. They're a consistent source of attack down while also bringing some damage mitigation and HP burn on the side.  

I agree that making more food is a good choice right now, but be carefull wich champs you are going to sacrifice. Definetly keep Coldheart for later use. Reliquary Tender is fantastic vs. Nether Spider in the Doom Tower, and Renegade may be usefull later on as well. Also keep all fusion rares.