Ebon Dragon against true believer shroud you have magic

[Zippy]

if I cast Ebon Dragon and other player has true believer but he also has a planeswalker can I target his planeswalker and redirect to him?

[Kenji]

No, you can't do that, because the planeswalker redirection effect only applies to noncombat damage. It also only works one way (from a player to a planeswalker), and not at all the other way around. Also, a planeswalker is not an opponent, so it could never be the target of a spell/ability that asks you to target an opponent.

306.7. If noncombat damage would be dealt to a player by a source controlled by an opponent, that opponent may have that source deal that damage to a planeswalker the first player controls instead. This is a redirection effect (see rule 614.9) and is subject to the normal rules for ordering replacement effects (see rule 616). The opponent chooses whether to redirect the damage as the redirection effect is applied.

To sum it up, a player with shroud is safe from Ebon Dragon's discard ability.