I don't know why you're doing this for Mystletainn but, Mystletainn's effect is first, Leyvaten is sent to graveyard, then, since Aklys is a equip card, it's effect is not activated and sent to the graveyard since it is no longer equipped, and you special summon Mystletainn.
I run Dragunitys almost religiously so. :D
No, only monsters who specifically say they do, gain such a bonus. Relinquished for example, is one. It gains a bonus depending on what it has equipped, as does Destiny Hero Plasma. Dragunity monsters do not, unless one does actually say so.
If an equipped monster finds itself no longer equipped to a monster for any reason, then it is sent to the graveyard.
Flint is sent to the graveyard
It mean that to trigger, they had to be sent to the graveyard while they were equipping a monster. That means if they were discarded from hand, or destroyed while face down, or destroyed because the equipped monster was turned face-down or was removed from the field, then they will not get their effect. But if it was equipped to a monster, and an effect destroyed it (or destroyed it and the monster simultaneously) then that effect will be applied.
Yes, Equip Spell Cards cannot exist on the field without their target. If the target leaves the field, the Equip Spell Card will be destroyed and go to the graveyard.
If you have Dragunity Aklys equipped to Evocator Chevalier, and you send Dragunity Aklys to the graveyard to activate Evocator Chevalier's effect, then Dragunity Aklys' own effect will trigger, it will wait for the chain Evocator Chevalier's effect started to resolve, and start a new one afterwards.
No, only monsters who specifically say they do, gain such a bonus. Relinquished for example, is one. It gains a bonus depending on what it has equipped, as does Destiny Hero Plasma. Dragunity monsters do not, unless one does actually say so.
Dragunity Aklys has a triggered effect when it is destroyed while equipping one of your monsters. This triggered effect targets and destroys one card on the field. If the opponent's side of the field is empty, then you must target one of your own cards instead. If there are no valid targets at all, the effect simply fails to activate.
No, Equip Cards simply 'fall off' when the monster they are equipped to is destroyed. They do not go to the graveyard, they are now just unattached.
If an equipped monster finds itself no longer equipped to a monster for any reason, then it is sent to the graveyard.
Yes. With the Continuous Spell Dragon Mastery (described in related link) in play, you can select 1 face-up monster you control once per turn, and equip it with 1 Dragon-type Dragunity monster from your hand. Also, each monster you control that's equipped with a Dragunity monster(s) gains 500 ATK.
Flint is sent to the graveyard
It mean that to trigger, they had to be sent to the graveyard while they were equipping a monster. That means if they were discarded from hand, or destroyed while face down, or destroyed because the equipped monster was turned face-down or was removed from the field, then they will not get their effect. But if it was equipped to a monster, and an effect destroyed it (or destroyed it and the monster simultaneously) then that effect will be applied.
Yes, Equip Spell Cards cannot exist on the field without their target. If the target leaves the field, the Equip Spell Card will be destroyed and go to the graveyard.
It does not count as fusion material if it is equipped to cyber dragon. In the event that it is equipped to cyber dragon during the fusion for cyber end dragon armored cybern would be treated as a normal equip spell and would be sent to the graveyard.
Handcuffs Dragon returns to the field in two ways. - If it is not equipped - if it destroyed by battle, it can become an S/T card equipped to the monster it destroyed. - If it is equipped - if the equipped monster is destroyed and Handcuffs Dragon sent to the graveyard, then it can Special Summon itself. So if it is not Equipped, it cannot special summon itself, only come back as an S/T card if destroyed in battle. If it's acting as an Equip card, it can only special summon itself, it can't re-equip itself to something immediately.
XYZ material monsters no longer count as being monsters on the field, any equip cards will fall off, they will go to the graveyard. Ekibyo Drakmord can only return to hand when it destroys the monster it equips. In this case it will simply go to the graveyard and can't return, it went there as its equip target became an invalid one.