[quote=@Ryougu]
[@GarlandDaHero]
Is this acceptable as a guardian?
[Hider=Guardian Monster:]
[b]SUMMONING CONDITION[/b]
When your LP is 1000 or less, tribute monsters until you have 1 left; guardian summon this card.
[img]https://www.yugiohcardmaker.net/ycmaker/createcard.php?name=Opportunistic+Arbiter&cardtype=Monster&subtype=effect&attribute=Wind&level=3&rarity=Rare&picture=http%3A%2F%2Fimg12.deviantart.net%2Feeae%2Fi%2F2009%2F364%2F9%2Fb%2Fdoes_god_play_dice_by_borda.jpg&circulation=FAKE&set1=&set2=&type=Machine+%2F+Guardian+%2F+Tuner&carddescription=This+card%27s+Guardian+Summon+cannot+be+negated.+When+Summoned%2C+Special+Summon+1+Synchro+Monster+from+your+Graveyard%2C+then+immediately+after+this+effect+resolves+Synchro+Summon+1+Synchro+monster+from+your+Extra+deck+using++monsters+you+control+as+Synchro+Materials%2C+including+this+card.+Your+opponent+cannot+activate+the+cards+or+effects+in+response+to+this+effect.&atk=100&def=100&creator=Some+Scumbag&year=2017&serial=66637268[/img]
[/Hider]
[/quote]

Looks okay to me.

Also, to answer your question, Extra Deck monsters go to the Extra Monster Zone if they're summoned through their respective summoning method or a card that treats a Special Summon as an Extra Deck summon. In all other cases, they go to the Main Monster Zone.

[quote=@Killfang96]
[@Ryougu]
Just be careful dueling me half my cards give extra deck monsters a giant pain in the rear. :P
[/quote]

Keep in mind that I WILL be using the banlist, so you can't use stuff like Djinn Releaser of Rituals unless they're not on the list.

[@AdmrlStalfos19]

Yeah that looks WAY too strong. I suggest changing the anti-leave-the-field effect to just protecting it from being targeted and/or destroyed by card effects, as well as reducing the ATK to 3500 or so and the DEF to 0, just for the Zombie-Type flavor.