First strikeFirst 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. (CR 702.7)
LandfallAn ability word has no rules meaning of its own. It groups abilities with similar themes; the text following it explains this card’s effect. (CR 207.2c) — Whenever a land you control enters,
goadCertain spells and abilities can goad a creature. Until the next turn of the controller of that spell or ability, that creature is goaded.
Goaded is a designation a permanent can have. A goaded creature attacks each combat if able and attacks a player other than the controller of the permanent, spell, or ability that caused it to be goaded if able. Goaded is neither an ability nor part of the permanent’s copiable values.
A creature can be goaded by multiple players. Doing so creates additional combat requirements.
Once a player has goaded a creature, the same player goading it again has no effect. Doing so doesn’t create additional combat requirements. (CR 701.15) each creature target player controls. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)