When a monster such as a Union, Necrofear or a Relinquished victim becomes an Equip, is it treated as a Spell or a Monster once it's on the field?

Case 1: I attempt to use Chaos Sorcerer's effect to remove Dark Necrofear from the game and get my monster back. Will it work?

Case 2: I attempt to use Msytical Space Typhoon to destroy my Relinquished victim. Will it work?

Case 3: I have an Aitsu/Koitsu combination and Element Valkyria on the field. Does Valkyria get both effects or just the 500 ATk boost?

Once equipped to a monster the original monster card that is now equipped (e.g. necrofear) is considered to be an equip magic card and so can be destroyed by mst

As for your other 2 questions, it wont be affected, its no longer a monster card with attributes etc.

1) Whenever a Monster Card becomes an Equip Card, it becomes an equip Spell Card and is no longer considered a Monster Card.

2) No, you cannot use a "Remove 1 face-up monster on the field" effect on a card that is a Spell Card. You can however, use an effect that destroys Spell/Trap Cards.

3) Yes, you can use Mystical Space Typhoon on a monster equipped to your Relinquished. Great for getting new monsters on it. :)

4) Element Valkyria will only gain 500 ATK points. Monsters that are Spell Cards sort of replace the Attribute symbol in the corner with the Spell symbol.

Unions say on them 'when equpped to a monster by this card's effect...'

So, does that mean that fi you use formation union to equip a Union monster, you don't get the effect?

Also, if Metallising Parasite - Lunatite is equipped to Maha Vailo, does it get 500 ATK?

If Kunai with Chain/Metalmorph is equipped to Maha Vailo, does it get the boos then?

1) No, Formation Union basically "forces" the Union Monster to equip to an APPROPRIATE monster at any time.

2) Yes, Maha Vailo will gain 500 ATK.

3) Yes, Maha Vailo will gain 500 ATK due to its effect when equipped by Metalmorph. Maha Vailo only cares that it is equipped, what by, it doesn't matter.

(Note: Kunai with Chain isn't out yet outside of Japan.)

So if I use Formation Union to equip Koistsu to Aitsu, does it get 3000ATK?

RONIN rules on Formation Union:

• The monster you equip the Union Monster to must be "appropriate", meaning the monster name written in the text of the Union Monster.

• The Union Monster is considered to be equipped 'by its effect' so any bonuses the Union Monster grants are granted if equipped with "Formation Union".

• A Union Monster that is "detached" during the Battle Phase using "Formation Union" can attack during that Battle Phase.

• If the player who would control the Union Monster already has 5 monsters on the field, you cannot activate "Formation Union" and choose the second effect.

So, yes, if you equip Union monsters using Formation Union, they will still get their effects, so Koitsu will still boost Aitsu.

note though if you destroy necrofear with mst. they wil get another monster because it was destroyed

No, they wont. Necrofear's text has been changed:

Dark Necrofear
(Labyrinth of Nightmare, Duelist League 2)
This card cannot be Normal Summoned or Set. This card can only be Special Summoned by removing from play 3 Fiend-Type monsters in your Graveyard. If this card is destroyed as a result of battle or by your opponent's card effect while it is a Monster Card, it is treated as an Equip Card during the End Phase of this turn, and equip 1 of your opponent's monsters with this card. As long as it is equipped with this card, you control the equipped monster.

Viewable here: http://www.upperdeckentertainment.co...errata_01.aspx

Since Necrofear isn't considered to be a Monster Card while it is equipped (It's considered an Equip Spell), it no longer gets to return again.

they errated it thats ridiculas. i just read kevin saying last night that they dident errate it oh well must be old. dark necrofear secks any ways though