Shimmering Barrier

First strike is a static ability that modifies the rules for the combat damage step. (See rule 510, “Combat Damage Step.”)

If at least one attacking or blocking creature has first strike or double strike (see rule 702.4) as the combat damage step begins, the only creatures that assign combat damage in that step are those with first strike or double strike. After that step, instead of proceeding to the end of combat step, the phase gets a second combat damage step. The only creatures that assign combat damage in that step are the remaining attackers and blockers that had neither first strike nor double strike as the first combat damage step began, as well as the remaining attackers and blockers that currently have double strike. After that step, the phase proceeds to the end of combat step.

Giving first strike to a creature without it after combat damage has already been dealt in the first combat damage step won’t preclude that creature from assigning combat damage in the second combat damage step. Removing first strike from a creature after it has already dealt combat damage in the first combat damage step won’t allow it to also assign combat damage in the second combat damage step (unless the creature has double strike).

Multiple instances of first strike on the same creature are redundant.

Defender is a static ability.

A creature with defender can’t attack.

Multiple instances of defender on the same creature are redundant.

Cycling is an activated ability that functions only while the card with cycling is in a player’s hand. “Cycling [cost]” means “[Cost], Discard this card: Draw a card.”

Although the cycling ability can be activated only if the card is in a player’s hand, it continues to exist while the object is on the battlefield and in all other zones. Therefore objects with cycling will be affected by effects that depend on objects having one or more activated abilities.

Some cards with cycling have abilities that trigger when they’re cycled. “When you cycle this card” means “When you discard this card to pay an activation cost of a cycling ability.” These abilities trigger from whatever zone the card winds up in after it’s cycled.

Some cards have abilities that trigger whenever a player “cycles or discards” a card. These abilities trigger only once when a card is cycled.

Typecycling is a variant of the cycling ability. “[Type]cycling [cost]” means “[Cost], Discard this card: Search your library for a [type] card, reveal it, and put it into your hand. Then shuffle your library.” This type is usually a subtype (as in “mountaincycling”) but can be any card type, subtype, supertype, or combination thereof (as in “basic landcycling”).

Typecycling abilities are cycling abilities, and typecycling costs are cycling costs. Any cards that trigger when a player cycles a card will trigger when a card is discarded to pay an activation cost of a typecycling ability. Any effect that stops players from cycling cards will stop players from activating cards’ typecycling abilities. Any effect that increases or reduces a cycling cost will increase or reduce a typecycling cost. Any effect that looks for a card with cycling will find a card with typecycling.