Arsenic is great and pretty rare. Great addition to any kind of deck with death in it, Immobows included.
Arsenic is not rare! at lest not now. Many many poison decks that are currently in the bronze arena give you arsenic from normal spins.
But to get started with arena grinding, an arsenic in an antabow is crucial... It deals so much more damage than the hammer.
Consideration list (not in order):
Arsenic: A great addition to immonova/antabows. Gives a lot of advantages in pvp/arena/AI3
Vampire stiletto: Not a top choice, but facilitates nova-less immogolems pretty well. The upgraded version, vampire dagger, is almost as good as upgraded arsenic in rainbows.
Lobotomizer: RoL hope is still a pretty good FG grinder to get started with. Also makes dimensional shield decks more potent.
Pulverizer: Probably the best rare here. It is very useful in FGbows, while remaining crucial in SNbows in late game.
Top not-to-choose list (not in order):
Morning star:. *stares at Divine Glory*
Druidic staff: It is pretty easy to get it from AI3. 2 of the elders have it.
Trident: It may look good, but it's almost useless for every aspect. An earthquake does much better.
Others:
Fahrenheit: Not that impressive. But if you're making a
-heavy deck for AI4 grinding, do consider a bit.
Discord: It mostly shines in arena and AI3. However, it's not very compatible with unupped farmers. This gem only shines in the veterans' pockets (who possesses a considerable amount of
).
Titan: Solid, powerful, straight-forward. As a steady source of damage output it might be OK. But still, it's not very compatible, even in upped decks unless you focus around it.
Eternity: Due to the fact that SGbow is outdated, it's less useful than pulverizer now... but it's OK in a ghostmare.
Owl's eye: Great CC, but not compatible in unupped grinders (again?!). However, in fun pvp rainbows it sees some use. Although octane has lots of these, it's not as bad as morning star... after all the CC is not bad.