Wow my excitement for this expansion ended faster than expected.
Is it not enough we need to suffer Jade for like 4-6 more months, you give druid a weapon that can't be removed before he has 10 mana crystals and he can do a 20 mana turn now? Cause just playing Ultimate fuck you wasn't enough for one turn :D
a 1/5 weapon is worth like 1.5 mana (lights justice) so for 5 turns you are getting poor value.. but it's atack on druid with hero power it's 2 damage so it's quite potent I guess the upside is either your turn only or barely relevant by the time it pops up if removed by opponent what you CAN do is to play medivh in the same deck and cast UI in the same turn that's actually VERY insane..
Since it doesn't say "empty" mana crystals, I suppose it does indeed refresh. Which means that if the meta is even slower, you can do 30 mana turns with Kun into Y'shaarj into Infestation for example. Doesn't seem realistic as of now, tho.