Wizard, refusing a challenge, still able to cast spells?

New player here.

So my Herald of Tzeentch in a Horror unit is charged by Ogres lead by the Ogre Tyrant general. The Tyrant issues a challenge - I politely refuse and slink off to the rear rank and my unit whilst losing combat is able to survive the instability.

During my next turn is my herald still able to cast spells from the rear rank?

Edit; We both checked the magic section of the BRB page 31 (choosing a target) and also page 102 regarding refusing a challenge (Boo! Hiss!) but there appears to be no restrictions.

ALSO...when does the wizard return back to the front rank?

Can't find anything that stops you casting however you couldn't cast anything that needs line of sight.

Again can't find anything that says when you come back to the front but I guess it would be the next combat phase when challenges are issued again which of course you could refuse again!

Could you return to the front rank on a reform (at the conclusion of the round of combat)?

mortiferum wrote:ALSO...when does the wizard return back to the front rank?

Remember it is no longer the rear rank. It now says:
The retiring character slinks off to the back ranks and is not allowed to attack that round - move the model into a rank where he's not in base contact with the enemy

So if you were a horde 10 models wide attacked by 3 wide Ogres, the Wizard could move to the edge of the front rank as that model is not in BtoB with an enemy model.
I think they changed this as what happens when you are charged in front and rear - now the model sits in the middle where he can not attack.

Otherwise I'd say that the refusing character would have to stay at the relocated position till the challenge has been completed (likely to just the one round). Otherwise I think characters can use the 'Make Way!' rule on Page 100.

As to Magic, I see no restriction on casting other than the 'TLoS' for Magic Missiles. Which would be interesting given what I said above: 10 wide unit - wizard relocates to the edge and gains LoS for his next magic phase. (Then again the other player could always reform to expand their frontage?).