I'm using a lightning sentry, death sentry trapsin. I already have a plague runeword. Should I make a chaos or another plague for the offhand?

I don't really understand what I need to be a beast of a trapsin.

Information is much appreciated.

To be a beast of trapsin, you need to not play d2r

+3Ls chaos if you want to make use of the ed% and ds% on plague, because you will want to whirl

or another 2/3 claw if you wanna go pure trapper, and in that case you wanna put plague offhand and have a fast base with ias% as your primary 2/3 claw
plague doesnt have enough ias on it

I have a 40ias, +3ls rare trap. Would that do?

And whirling?? What's the point of fhe whirlwind?