Follow
There's a difference!
Reign: to rule, as in a monarch
Rein: to guide using straps, rope, or other horse tack, "to rein in"
"To reign in hell" : what Satan wants to do
"To rein in hell" : what God wants to do
@dclr42 rein mean much more than that or could mention it means a bit more:
rein (as Noun or Verb)
1. [what you said] strap or rope]
2. means of control
3. keep in check
(approx)