If an effect begins to apply to Crystalline Resonance before it becomes a copy of another permanent, that effect will continue to apply.

If Crystalline Resonance becomes a copy of an object with a set of linked abilities (for example, one ability that exiles a card and another that refers to the card “exiled with” the object), that link only lasts as long as Crystalline Resonance is copying that object. If it stops being a copy of that object and then becomes a copy again later, the link is lost.

If Crystalline Resonance becomes a copy of an Aura, it’s put into its owner’s graveyard unless it’s somehow attached to an appropriate object or player already. If it becomes a copy of an Equipment and is attached to a creature, it’ll become unattached when it becomes an enchantment again.

If Crystalline Resonance becomes a copy of a legendary permanent you control, you’ll put one of them into its owner’s graveyard.

If Crystalline Resonance’s ability triggers multiple times in a turn, then each time one of those abilities resolves, it will overwrite whatever Crystalline Resonance is copying. Crystalline Resonance will wind up as a copy of the permanent targeted by the last ability to resolve. As your next turn begins, all instances of the ability will wear off at the same time.

Crystalline Resonance copies the printed values of the target permanent, plus any copy effects that have been applied to it. It won’t copy counters on that permanent or effects that have changed its power, toughness, types, color, or so on. Notably, it won’t copy effects that made the target permanent become a creature.

Triggered abilities from cycling a card and the cycling ability itself aren’t spells. Effects that interact with spells (such as that of Cancel) won’t affect them.

If Crystalline Resonance becomes a creature the same turn it enters the battlefield, you can’t attack with it or use any of its abilities (if it gains any) unless it has haste.

Crystalline Resonance’s copy effect wears off immediately before your next turn begins.

If another permanent becomes a copy of Crystalline Resonance, it will become whatever Crystalline Resonance is copying and it will also have its ability.

If Crystalline Resonance copies a permanent that’s copying something else, it will become whatever the target is copying.

If Crystalline Resonance becomes a copy of a planeswalker, it won’t receive loyalty counters for that planeswalker’s starting loyalty. Unless it already has loyalty counters on it somehow, it will be put into its owner’s graveyard.

You can cycle a card even if it has a triggered ability from cycling that won’t have a legal target. This is because the cycling ability and the triggered ability are separate. This also means that if either ability is countered (with Disallow, for example), the other ability will still resolve.

Some cards with cycling have an ability that triggers when you cycle them, and some cards have an ability that triggers whenever you cycle any card. These triggered abilities resolve before you draw from the cycling ability.