Legendary Creature — Efreet Wizard
Magecraft — Whenever you cast or copy an instant or sorcery spell, Veyran gets +1/+1 until end of turn.
If you casting or copying an instant or sorcery spell causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
2/2

Magecraft treasure maker doubled by Veyran for explosive ramp.

Magecraft card draw that Veyran doubles.

Spellslinger commander making tokens off instants/sorceries.

Izzet spellslinger payoff drawing and pinging on casts.

Token generator triggered per instant/sorcery, doubled by Veyran.

Damage on each instant/sorcery cast, doubled by Veyran.
→ Infinitely large creature until end of turn, Infinite magecraft triggers
→ Infinitely large creature until end of turn, Infinite magecraft triggers, Infinite storm count
→ Infinitely large creature until end of turn, Infinitely powerful creatures you control until end of turn, Infinite magecraft triggers
→ Infinite death triggers, Infinite ETB, Infinite LTB
→ Infinite colored mana, Infinitely large creature until end of turn, Infinite power for any creature
→ Infinite copies of instant and sorcery spells on the stack, Infinite death triggers, Infinite ETB
Veyran, Voice of Duality's last ability causes each of your magecraft abilities, including Veyran's own, to trigger an additional time.
If an effect creates a copy of an instant or sorcery spell, this will also cause the magecraft ability to trigger.
Some effects instruct you to copy an instant or sorcery card in a zone other than the stack. These copies do not cause magecraft abilities to trigger. However, most effects that do this also allow you to cast the copy, and casting the copy will cause magecraft abilities to trigger.
Each magecraft ability has a different effect, although they all have the same trigger condition, whenever you cast or copy an instant or sorcery spell.
Veyran's effect doesn't copy the triggered ability; it just causes the ability to trigger again. Any choices you make as you put the ability on the stack, such as modes and targets, are made separately for each instance of the ability. Any choices made on resolution are also made individually.
If an effect creates multiple copies of an instant or sorcery spell, magecraft abilities trigger once for each copy created by the effect.
If you somehow control two Veyrans (which would be poetic), you casting an instant or sorcery spell causes abilities to trigger three times. A third Veyran (less poetic) causes abilities to trigger four times, and so on.