Coloseum Pay-Wall

Yeah, you're hitting a designed wall. 

Every time you go up a tier, you lose a summoned toon. Obviously each tier is easier with more attackers, right? So even if you're skilled and even if you buy boosts, you get to a point where you're forced to either spend more money (at your level, it would probably be a lot bc you've already bought the cheaper stuff) or wait til they release the next character so you can add one more person to your squad, and with the extra damage output of one more toon you should be able to hit 40%. 

I wish I had better news for you, but they did design it to extract $$. 

CG_Meathead​ what do you think about that?

Thanks for the answers. I bought some Era toon upgrades for dollars at the start, and my characters reached level 44 (Keyla) and 39 (Vel). However, I still can't get the 40% box that gives materials to upgrade a toon to a higher tier. My best result is around 30% - barely - on the Tier 4 boss.

I'm also spending crystals to get them to 5 stars, but it changes nothing. I already have Keyla at 5 stars and Vel is almost at 5 stars. For about two weeks now I haven't been able to get even a single level up without spending real money.

I have the Era currency and the first material needed for the upgrade, but I just can't get the second one.

I've tried putting them on auto, attacking the bosses manually, and even following YouTube guides. Nothing changes. It just feels like some kind of RNG that keeps me stuck around 30% on every boss.

I even started to think that this ridiculous Era system that CG came up with works in such a way that if someone spends some money at the beginning and then stops, they are basically forced to wait until completely free-to-play players catch up to their stage before they can start getting anything better from the bosses.

The 40% box gives 75 materials, but I need 100 to upgrade Keyla and 50 to upgrade Vel, and I just can’t get that box on any boss.

It’s also possible that in order to get the 40% box on Tier 4 you actually need another released character from the Era, or maybe even several of them. If that’s the case, then it’s an even bigger scummy move from CG.

I think you're forgetting that early in the STLuke era things were much the same. 

Early boosts to the first toon of each era helps you cascade forward and stay on a good developmental path. That initial boost costs a significant amount, but less than 4k crystals. 

I spent less than 10k on Kleya (6k for shard pack and prob ~2.8k on mats/credits but I'm not sure exactly, it could have been more) and 6k on Vel (shards only). Right now I'm Lvl 29/27, and I have the mats to be 29/29, just waiting on a few more credits which come quickly at the end of the Episode track. 

That might be beyond your budget, but I promise that with the right boosts at the right moment, you can get yourself rolling. The hardest part will always be when you reach a new boss tier and are trying to hit 10%. If you're stuck there and you have crystals, you might consider buying mats. (Shards don't help. I buy them for other reasons.)

If you're stuck somewhere else, why not tell us where you're stuck % wise, on what tier, and what the levels of your toons are, and we can maybe help? Getting stuck temporarily is fairly normal, but getting stuck for more than 5/6 days is definitely not. If you've been stuck for 5 days, we'd love to help get you unstuck. 

I've had relatively steady progression, but I have used crystals to get more Era Level currency at least twice.  I have not bought the Episode pass this month.  

This is not my experience. I’ve been levelling regularly and have begun reaching t3 on the bosses.