I would use immobilise and aura of dismay. Basically immobilise there captain and well kill him lol. Then just use aura of dismay from every turn onwards when you have won piority and they wont be able to charge you unless they pass their courage test which is very very unlikely.

You wouldn't take him. You need to make your decision based upon what you know about your opponent. If he never uses mounted warriors and only uses cheap heroes than don't take him. My opponent always uses calvary because I don't have them so I know that he will likely include them in his force so I take radagast and he makes a very big difference.

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“But God demonstrates his own love for us in this: While we were still sinners, Christ died for us.” -Romans 5:8