diff --git a/data/rulesets.ts b/data/rulesets.ts
index becf52f6436c..7c9bdc695091 100644
--- a/data/rulesets.ts
+++ b/data/rulesets.ts
@@ -110,24 +110,28 @@ export const BattleFormats: {[k: string]: FormatsData} = {
 			for (const set of team) {
 				if (set.species === 'Kyurem-White' || set.species === 'Kyurem-Black') {
 					if (kyuremCount > 0) {
-						return ['You cannot have more than one Kyurem-Black/Kyurem-White.'];
+						return [
+							`You cannot have more than one Kyurem-Black/Kyurem-White.`,
+							`(It's untradeable and you can only make one with the DNA Splicers.)`,
+						];
 					}
 					kyuremCount++;
 				}
-				if (set.species === 'Keldeo-Resolute') {
-					if (!set.moves.includes('secretsword')) {
-						return ['Keldeo-Resolute needs to have the move Secret Sword.'];
-					}
-				}
 				if (set.species === 'Necrozma-Dusk-Mane') {
 					if (necrozmaDMCount > 0) {
-						return ['You cannot have more than one Necrozma-Dusk-Mane.'];
+						return [
+							`You cannot have more than one Necrozma-Dusk-Mane`,
+							`(It's untradeable and you can only make one with the N-Solarizer.)`,
+						];
 					}
 					necrozmaDMCount++;
 				}
 				if (set.species === 'Necrozma-Dawn-Wings') {
 					if (necrozmaDWCount > 0) {
-						return ['You cannot have more than one Necrozma-Dawn-Wings.'];
+						return [
+							`You cannot have more than one Necrozma-Dawn-Wings`,
+							`(It's untradeable and you can only make one with the N-Lunarizer.)`,
+						];
 					}
 					necrozmaDWCount++;
 				}
diff --git a/sim/team-validator.ts b/sim/team-validator.ts
index 4aeac1b09957..c34c0643f51d 100644
--- a/sim/team-validator.ts
+++ b/sim/team-validator.ts
@@ -1132,8 +1132,8 @@ export class TeamValidator {
 		const species = dex.getSpecies(set.species);
 
 		if (species.name === 'Necrozma-Ultra') {
-			const whichMoves = (set.moves.includes('Sunsteel Strike') ? 1 : 0) +
-				(set.moves.includes('Moongeist Beam') ? 2 : 0);
+			const whichMoves = (set.moves.includes('sunsteelstrike') ? 1 : 0) +
+				(set.moves.includes('moongeistbeam') ? 2 : 0);
 			if (item.name !== 'Ultranecrozium Z') {
 				// Necrozma-Ultra transforms from one of two formes, and neither one is the base forme
 				problems.push(`Necrozma-Ultra must start the battle holding Ultranecrozium Z.`);
@@ -1178,13 +1178,27 @@ export class TeamValidator {
 				if (dex.gen >= 8 && (species.baseSpecies === 'Arceus' || species.baseSpecies === 'Silvally')) {
 					// Arceus/Silvally formes in gen 8 only require the item with Multitype/RKS System
 					if (set.ability === species.abilities[0]) {
-						problems.push(`${name} needs to hold ${species.requiredItems.join(' or ')}.`);
+						problems.push(
+							`${name} needs to hold ${species.requiredItems.join(' or ')}.`,
+							`(It will revert to its Normal forme if you remove the item or give it a different item.)`
+						);
 					}
 				} else {
 					// Memory/Drive/Griseous Orb/Plate/Z-Crystal - Forme mismatch
-					problems.push(`${name} needs to hold ${species.requiredItems.join(' or ')}.`);
+					const baseSpecies = Dex.getSpecies(species.changesFrom);
+					problems.push(
+						`${name} needs to hold ${species.requiredItems.join(' or ')} to be in its ${species.forme} forme.`,
+						`(It will revert to its ${baseSpecies.baseForme} forme if you remove the item or give it a different item.)`
+					);
 				}
 			}
+			if (species.requiredMove && !set.moves.includes(toID(species.requiredMove))) {
+				const baseSpecies = Dex.getSpecies(species.changesFrom);
+				problems.push(
+					`${name} needs to know the move ${species.requiredMove} to be in its ${species.forme} forme.`,
+					`(It will revert to its ${baseSpecies.baseForme} forme if it forgets the move.)`
+				);
+			}
 
 			// Mismatches between the set forme (if not base) and the item signature forme will have been rejected already.
 			// It only remains to assign the right forme to a set with the base species (Arceus/Genesect/Giratina/Silvally).