I would suggest getting a rarer rare from the quest, because some are extreamly hard to get any other way, others are pretty easy.
Trident -> water/earth... which elements do you use the least in your rainbow if it isn't water/earth?
(mine uses 6 earth quanta pulverisor + 2 enchants and 8 water purify + nymphs tears, that latter card only added because of my lack of using water, in a deck with 19 upgraded quanta pillars and 4 supernovas, I'm rarely short on these elements)
Eternity -> in my opinion the best card in the game. It has so many different uses offensive and defensive and is greatly increased in power if you have a fallen druid/elf on the field.
Pulverisor -> is getting a nuke but is probably still going to be the 2nd best rare weapon.
Vampire dagger -> is getting stronger, it'll be as good as the druidic staff soon.
For rarity, I've won many games T50, False Gods, pvp and AI3 and this is my current rare count: (I chose a fahrenheit as my quest reward all that time ago)
2x Discord
1x arsenic
3x titan
6x pulverisor
4x druidic staff
6x fahrenheit
0x trident
7x morning star
8x owl's eye
9x eternity
5x vampire stelletto
4x electrocutor
Note: for rares that I have 6 of, I may have sold off any spares I had since you can't use more then 6 in any given deck.
Note2: ever since a post in this thread I started collecting rares which I had more then 6 of again, so if I have 6 or more rares I may have sold a few of that one before that.
EDIT: updated rare count (it'd be nice for a few others to post thier rare count so we can get a better idea of rare's rareness