FIQ:
The level 20 and 40 rewards are pretty reasonable. Shards and electrum are quite meaningful at those levels. The level 60 reward is good, too, because nymphs are always good to get, and 5k electrum is still useful at this point, although less so.
I don't like the level 80 reward, though. 10k electrum is totally useless at level 80. I'm level 74, and I already don't have any more use for electrum, as all I need for a full set of cards are a few of the newest shards, and I don't even need electrum for that, since they come upped when I get them on special spins. The second nymph is also a good idea. The mark not so much, though; in practical play, they're only really useful against quicksand, and to a lesser degree other PC, and they're really more just intended as pvp trophies.