Vigilance
When Djeru enters, you may search your library for a planeswalker card, reveal it, put it into your hand, then shuffle.
If a source would deal damage to a planeswalker you control, prevent 1 of that damage.
If multiple sources would deal damage to one or more planeswalkers you control at once (for example, several attacking creatures), 1 damage from each of those sources to each of those planeswalkers is prevented.