So I’ve been playing since April2019 and the game has been good to me with giving 4star troops so I have multiple in all colours, but none in Blue.
Until today. I finally got a 4star troop from tournament ETT. Unfortunately it was Crit as opposed to Mana.
Do I throw my over 200 blue feeder troops in anyway and get it levelled as still better than what I have been using? Or hold on in the hope that RNG might cooperate and finally give me a mana version?
Do you already have HA 9? If so try it and you will get your blue mana probably a lot faster than with coin summons.
If not I’m not sure, I have done it and now have in two colors leveled crit troops but no max manatroops, in the other colors I’m already at my third set of manatroops. I regret it, pretty much every day and if I would start again, I would definitely wait.
I have also waited for my first blue manatroop nearly 2 1/2 year and when I finally got her I was able to level the new troop nearly to max because of the many feeders I collected over the time.
I haven’t worried about HA9 in the same way I have yet to touch HA10. Levelled my HA just high enough to get me trainer heroes currently as whilst I have enough 4star troops in Purple (4M 1C) Red (3M 2C) Green (3M 2C) Yellow (2M 2C) I dont really have the additional I’d trade away.
For that reason I’ve been just doing ETT pulls as and when and a couple of 10pulls as I’m not using gems currently for heroes till I level what I have.
I do have the same scenario in yellow where I’d got the mana troop versions late so despite having at least lvl 18 in PRG (and secondary close to 11) I have lvl 13 in yellow plus a lvl 11 crit…
Wait for mana. I’ve also got crit troops early in the game and mana troops only after about two years, so I worked on crit troops for a long time. I’ve now abbandoned my crit troops between levels 24 and 28 and am working on a mana troops set to replace them… of course, the process is long and painfull… I regret investing all those feeders in crit troops, but not getting mana troops for such long time is unberable…
Sure is I keep looking at my costumed richard and Kiril thinking just need level 5, but nothing… 
RNG gonna RNG I guess
Another +1 wait for mana, as @ferg said, HA9 is good and faster while waiting and hoarding ETT for Ninja Event. I was paused HA10 and do HA9 about 8x, and gave me one Mana Dark and one Mana Yellow. And if you retrain, make sure you do not input blue crit, just in case…
The other HA is HA6 (stanby) for iron stock and troop feeder.
Wait…
You do not have any overload Crit troop, I was only retrain my 6th or 5th or 4th Crit troop.
But If I were you, I still doing HA9, just keep only one Crit is enough for a moment.
I guess I could set one of my crit troop for HA9, looking at what I have now I guess one of the red or green?
I totally relate to @Ian487 's experience.
It took forever, for me, to get purple and yellow mana troops (considerably more than two years).
As a result those two are way behind what they should be and it does take a toll.
I say hold, because that’s the only way to have a reasonable mana troop in a decent time when it finally shows up.
I would level it, but only to a reasonable level, like 5 or 10. Then you will benefit more from using this troop, while keeping the excess feeders to level your mana-troop when it finally comes.
– edit - and you will use your crit-troop for a long time, even if you get a few manatroops; as troop for a blue tank, or in addition to your manatroop
I just realized I had a similar problem with the OP. Last week I started researching the HA9. I have two 4* yellow troops to spare. I don’t think we need more than 5 4* for each color, so I’ll start to gamble on HA9.
In first 18 months I got no purple and blue mana troops and just finished HA9. In 5 weeks running it gave me 2 purple and 1 blue mana troops + I got one each from ninja portal. So yeah, go for it and do not hesitate to retrain 2nd, 3rd or 4th critical troop in each color.
Kilted, I’m about 2 & 1/2 years of playing this game and up until about 3 months ago, I had only ever pulled 1 blue mana troop and 2 blue crit troops. I had multiple mana/crit and even ninja troops in the other colors. So I just stuck non blue lvl 4 crit troops in my HA9 until I pulled a blue mana troop.
Funny, this last ninja tower I did some mass pulls with tokens and gems and finally pulled another blue mana troop, so that makes 3 in all that time playing.
Good luck on getting a blue mana troop. I feel your pain oh so well and I’m rooting for you!
i would take WaVe’s advice and level it to somewhere reasonable, like when the critical stat first upgrades or defense hits 20% or something.
i had a bounty this last Ninja Tower: my first, second, AND third blue mana troops, and my first and second green mana troops. i haven’t been waiting two years, but i was still glad i saved all those feeders instead of feeding them into my blue crit troop or my blue and green ninja troops. i do think the other troop types have their uses and should be leveled eventually, but in terms of leveling priority, i would definitely level mana troops before the other types, so save the feeders.