As you cast Honorable Passage, first you announce the spell and put it on the stack (CR 601.2a). Then you choose the target for the spell (CR 601.2c). Finally, you pay all costs (CR 601.2f, 601.2g, 601.2h). You do not choose the source of damage until Honorable Passage resolves (CR 608.2d).

Once Blinding Flare is put on the stack and cast, triggered abilities will go onto the stack on top of it in AP-NAP order (CR 603.3, 603.3b). Since it is your turn, Horobi’s trigger will go on the stack first, then Petrahydrox’s trigger will go on the stack on top of it (CR 101.4, 102.1, 405.3, 405.5). Petrahydrox is returned to your opponent’s hand. Horobi’s trigger will do nothing (CR 400.7).

Blitz and Dash both function similarly to each other, as they both represent static abilities that function while the spell is on the stack, and that will create a delayed triggered ability that will exist independent of its source (CR 603.7a, 603.7c, 608.3g, 702.109, 702.152). Thus, Dress Down will not prevent Mayhem Patrol and Ragavan from leaving the battlefield due to Blitz and Dash, respectively. Arcbound Worker and Ivy Elemental both have replacement effects that allow them to enter the battlefield with 1/ 1 counters (CR 614.1c). However, when these creature spells are resolving, the game looks at the characteristics of the creature as it would exist on the battlefield to determine which replacement effects to apply, including continuous effects that already exist and would apply to that creature (CR 614.12). Since Dress Down removes the static abilities generating these replacement effects, they will not apply as Arcbound Worker or Ivy Elemental enter the battlefield (CR 603.6d). Each creature will be put into your graveyard as a state-based action (CR 704.5f). Evoke includes a triggered ability that triggers when Fury enters the battlefield and its Evoke cost was paid (CR 702.74a). Dress Down removes this ability immediately when Fury enters the battlefield, so it will not trigger (CR 603.6a, 603.6b). Fury will remain on the battlefield.

Infect changes the results of dealing damage. Instead of marking damage on creatures, a source with Infect causes the creature’s controller to put that many -1/-1 counters on that creature (CR 120.3, 702.90c). Ironscale Hydra’s ability is a prevention effect that applies before damage is processed into results (CR 120.4b, 615.1a). Since Giant Growth modifies Phyrexian Crusader’s characteristics, Phyrexian Crusader is the source of all five damage for Ironscale Hydra to prevent (CR 510.1a).

Since Fellwar Stone is a creature, No Mercy’s ability will trigger when it deals combat damage (CR 510.2, 510.3a, 603.2). No Mercy’s ability does not target, so it will resolve normally (CR 115.1d, 608.2b). The Fellwar Stone is destroyed because it is the same object that dealt damage and caused the No Mercy ability to trigger, even though it is no longer a creature (CR 608.2c, 608.2j).

In the steps of casting a spell, targets are chosen before costs are determined or paid (CR 601.2c, 601.2f, 601.2g). The check for legal casting is also done before costs are determined and paid (CR 601.2e). Costs are determined by taking the mana cost of the spell, adding additional costs, then subtracting cost reductions. Hex’s mana cost is {4}{B}{B}, increased by {4} due to the abilities of the two Boreal Elementals, then reduced by {6} due to the ability of Battlefield Thaumaturge, resulting in a final cost of {2}{B}{B} (CR 601.2f). Phyrexian Altar is a mana ability, so it may be activated once the total cost is locked in (CR 601.2g, 605.1a). Once the cost is paid, the spell becomes cast (CR 601.2h, 601.2i, 601.5). After the check for legality before costs are paid, the targets are not rechecked for legality again until the spell attempts to resolve, and it will still resolve if at least one target is still legal (CR 608.2b).

While on the stack, Blazing Specter is a creature spell and thus a legal target for Hallow (CR 112.1). Hallow’s prevention effect will continue to apply to the permanent that the Blazing Specter creature spell becomes (CR 400.7b). Hallow will prevent the damage that Blazing Specter deals in combat and cause you to gain that much life (CR 615.5, 615.6). Blazing Specter’s ability will not trigger (CR 603.2h, 615.6).

Once Brimaz is declared as a blocker for Elvish Berserker, both creatures have a triggered ability that triggers (CR 509.1i, 509.4a, 509.5a, 509.5c). These abilities will be put on the stack in AP-NAP order (CR 603.3b). When Brimaz’s triggered ability resolves, you create a Cat Soldier token blocking Elvish Berserker (CR 608.2c). This does not trigger Elvish Berserker’s ability again (CR 509.1h, 509.5c). Your opponent will choose where the Cat Soldier token goes in the damage assignment order, before or after Brimaz (CR 509.7). When Elvish Berserker’s triggered ability resolves, it will get 2/ 2 until end of turn (CR 608.2h). When Flash Foliage resolves, your opponent will choose where the Saproling token goes in the damage assignment order, but may not change the relative positions of Brimaz and the Cat Soldier token (CR 509.7). This does not trigger Elvish Berserker’s ability again (CR 509.1h, 509.5c).

Cascade’s effect creates a window where you may cast the exiled card with mana value less than Violent Outburst (CR 702.85a). This spell is being cast from exile, so Grafdigger’s Cage will not apply (CR 702.85a). However, Teferi, Time Raveler’s effect prevents you from casting spells while the stack is not empty, so you may not cast Living End (CR 101.2, 307.5, 601.3). Since it was exiled and not cast, Living End will be put on the bottom of your library in a random order with the other exiled cards.

Reflecting Pool produces mana based on the type of mana your lands “could produce.” These types are determined by seeing what the abilities of your lands would produce if they resolved at that moment, applying any applicable replacement effects (CR 106.7). River of Tears’ ability contains a self-replacement effect, so it will always be checked when determining what River of Tears can produce for purposes of Reflecting Pool (CR 614.1a, 614.15).

Arboreal Grazer does not assign damage in the first combat damage step since it has 0 power when damage assignment happens (CR 510.1a). Nessian Courser assigns and deals three damage in the first combat damage step, since it has First Strike from the Archetype of Courage (CR 510.1, 510.2, 510.4, 702.7b). Since Arboreal Grazer had First Strike as the first combat damage step began, it will not assign damage in the second combat damage step (CR 510.4, 702.7b).

The end step will end once the stack is empty and both players pass in succession (CR 500.2). Turning Blistering Firecat face-up is a special action that doesn’t use the stack and you will receive priority back again once that action is complete (CR 116.2b, 116.3). Taking this special action breaks the succession of priority passes required for the step to end, so your opponent will receive priority back and may cast Shock (CR 117.1, 117.3d, 117.4).

Llanowar Elves gains hexproof from Blossoming Defense, so it is no longer a legal target for Frost Breath (CR 608.2b, 702.11b). Since at least one target is still legal, Frost Breath will continue to resolve (CR 608.2b). It cannot tap the Llanowar Elves since it is an illegal target for that portion of the spell. Frost Breath creates a continuous effect that affects game rules, so that portion of the effect will not apply to Llanowar Elves (CR 608.2b).

As Muse Vessel’s second ability resolves, it will identify any cards exiled with Muse Vessel’s first ability through last-known information since the Muse Vessel is no longer on the battlefield (CR 113.7a, 406.6, 607.2a, 608.2h). Muse Vessel’s second ability creates a continuous effect that permits the casting of the chosen card (CR 601.3). However, this continuous effect does not supersede the timing restriction on casting creature spells (CR 117.1, 117.1a, 608.2g).

The abilities of each enchantment create replacement effects that will apply to your next card draw (CR 611.2a, 614.1). Either one can apply, so you will choose the order that the effects apply (CR 616.1). If you choose Thought Reflection first, then both Words of Wilding effects will apply to the subsequent card draws, creating two 2/2 green Bear creature tokens (CR 616.1f). The effects from Words of Wilding are not optional, so both must apply in this case. If you choose Words of Wilding first, then Thought Reflection can no longer apply, so you will only create one 2/2 green Bear creature token and draw no cards (CR 616.1f).

Notion Thief will not apply to the first card you draw from the turn-based action during your draw step, so you will draw that card and take one damage from Spiteful Visions’ second ability (CR 504.1, 603.2). Notion Thief will apply to the card draw from Spiteful Visions’ first ability, so your opponent will draw that card instead and take one damage from Spiteful Visions’ second ability (CR 603.2, 614.1, 614.6). Strategic Planning puts a card into your hand, but this does not count as a card draw (CR 121.5). Notion Thief will not apply to it and Spiteful Visions will not trigger (CR 614.7). You have drawn one card and added one card to hand while casting one card, so you have three cards in hand and have taken one damage. Your opponent has drawn one card and cast one card, so they have two cards in hand and have taken one damage.

“Phyrexian” is a valid creature type and is one of Ichorclaw Myr’s creature types (CR 205.3m). Metallic Mimic’s third ability will apply to Ichorclaw Myr as it enters the battlefield (CR 614.1d, 614.12). Mirrorweave turns both Alpine Watchdogs into copies of Metallic Mimic, but the choice of “Phyrexian” is not a copiable value (CR 707.2, 707.6). The Alpine Watchdogs did not have a creature type chosen as they entered the battlefield, so their third ability will do nothing (CR 607.1, 607.2d).

Effects that modify power and toughness apply in a system of sublayers before timestamp order is taken into account (CR 613.4). First, the Aquamoeba’s printed power and toughness are 1/3 (CR 613.1). There are no characteristic-defining abilities to apply (CR 604.3, 613.4a). Then Sudden Spoiling’s effect is applied, as it sets Aquamoeba’s power and toughness to, specifically, 0/2 (CR 613.4b). Then Spidersilk Armor and Gather Courage are applied in timestamp order, as they modify power and/or toughness without setting them to a specific number, to make Aquamoeba a 2/5 (CR 613.4c). Finally, Aquamoeba’s power-and-toughness switching effect is applied to make Aquamoeba a 5/2 (CR 613.4d). While Sudden Spoiling removes Aquamoeba’s activated ability, it will not retroactively stop the ability from being activated (CR 113.7a).