Among the many failures by Plarium is the Clan Quest to win a Rare Shield from a Campaign Battle. This looks easy so some players might rush to take it, but this quest is a disaster!
On the picture below you see my Clan-mate ended up doing 300 campaign battles before he managed to find a single Rare Shield. This is a massive waste of resources!
So be careful, don't just rush to take this quest unless you are willing to pay the price for it.
Update:
Adding various useful comments from others and myself on Reddit regarding this:
1)
Blackeagle525: A clan mate of mine said it took him 2100+ energy. Yeah, this is another example of poor design.
2)
kshoggi: Should take about 250 energy if you just wanna get it over with and run normal campaign. --> MY ANSWER: COSMOS_DolyGames: 1) 250 energy that you quote is a calculated expectation. As it is fully RNG you can see that people are reporting significantly higher numbers also. (2) Even if we take 250 energy, that is a big damage on the account because you get squat from doing 50 Normal Boss level runs. With those 250 energy you could have leveled up 3 x 3* champions from level 1 to level 30 and another 3 x 2* champions from level 1 to level 20 and on top of that gotten a decent amount of silver income. Or you could have spent it on dungeon runs to get EXP/artifacts/silver as well as ~250 points for Dungeon event as well as Divers event.
3)
When I was asked to give details:
I thought it was widely known that Boss levels are significantly worse. But OK, here you go:
Normal 12-7 gives per run 10380 EXP (@x2) + 6150 Silver + useless 1* 2* junk, let's say 2000 Silver and costs 5 Energy per run
Brutal 12-3 gives per run 34608 EXP (@x2) + 10550 Silver + about 5000 silver worth of gear avg. per run and costs 8 Energy per run
For 250 Energy one can run 50 of those Normals and 31 of those Brutals
The above Normal would generate 519k EXP + 307.5k Silver from the run + 100k silver from the junk
The above Brutal would generate 1081k EXP + 330k Silver from the run + 156k Silver from gear
The difference, doing the above Normal, would mean a loss of 562.5k EXP + loss of 78.5k Silver.
And that's just for 250 Energy while you can see some people reported having to spend 2000 Energy before they got the item.
On 2000 Energy the loss would be, of course, more = loss of 4.5 mil EXP + loss of 627.5k Silver
4)
bigkino217: i had to check if my clan mate who took this actually knew how to do it. he did, it just took him over 1k energy