Sending a card to the Graveyard is a cost.
If the first attack of a monster equipped with "Twin Swords of Flashing Light – Tryce" is negated by "Magic Cylinder", the monster can still perform the second attack.
When you declare the second attack of a monster equipped with "Twin Swords of Flashing Light – Tryce", and the "Twin Swords of Flashing Light – Tryce" is destroyed during the Battle Step with "Mystical Space Typhoon", the monster is no longer capable of performing the second attack, and a replay occurs.
If a monster that normally attacks twice like "Hayabusa Knight", "Gray Wing", or "Tyrant Dragon" is equipped with "Twin Swords of Flashing Light – Tryce", it doesn't get a third attack.
You can equip "Twin Swords of Flashing Light – Tryce" to "Injection Fairy Lily" and you can use her effect for each attack.
If "Twin Swords of Flashing Light – Tryce" is equipped to a monster affected by "Diffusion Wave Motion", it can only attack twice.
If "Dark Blade" equipped with "Kiryu" is also equipped with "Twin Swords of Flashing Light – Tryce", and attacks twice, and "Kiryu" is then "detached" with "Combination Attack", "Dark Blade" can attack 1 more time (not 2 more times).
If "Airknight Parshath" is equipped with "Twin Swords of Flashing Light – Tryce" and attacks twice, you can draw twice.