Purplenum is a good ID, especially if you like Mechguns. Whitill can I think can make Guld Milla so thats a good ID to.
I fyou want good weapons early, or like rifles, go greenill, but If you want better stuff later in the game then go with Purplenum
Greenill's Guard Wave is great.
Yea. Rifles are always good because you can stay far away from your enemys. But mechguns are good for bosses because your usually in a small space.
I use both, a while ago I wish my char had been a greenill but now I'm happy he is a purplenum
I haven't found any rifles yet with my Greenill... bad luck I guess. My next character will probably be a RAcast/Viridia, but I'm gonna wait awhile, obviously.

I've found a few interesting things with my Purplenum, but you do get bored of finding H&S25 Justice guns after awhile.
Redria actually isn't a bad ID, although slicers are their apparant specialty. Besides being the only character that can find God/Battles, they can find other good stuff (I found two Guilty Lights in Ult Caves a little while ago).
when your purplenum gets to ult mode you get alot more things that are very good, I just got mine to ult and already have gotten 3 L&K14Combats o_0
Viridia is pretty good for rangers

Doesn't that mostly find shots though?
Viridia finds shots primarily, in a way, I'd say Viridia finds a little bit of everything. Excellent Tower.