Re: Skill Challenges

You and Ebony can make any number of primary skill checks. Non-primary checks might count depending on plausibiity. So I'm afraid I'm not convinced by the use of Arcana and Diplomacy

Re: Feat

You can always ride mounts, no problem. What the Mounted Combat feat does is to let you to access the special abilities of your mount, and use your Athletics, Acrobatics, Endurance, and Stealth scores instead of its own if yours are higher.

In your case, the mechanical benefits of taking the feat are:
1. No need to take -2 penalty if it makes an attack roll
2. Ivory can take advantage of the dire wolf's "Pack Hunter" ability

As for the chariot, sure, why not. It's just a repurposed wagon, so cost of 20 GP and carrying capacity of 1 short ton.

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