REDU format ruling
Destiny HERO - Dasher

Nearest-era rulings (Tengu, Sept 2011) — no REDU-specific archive exists.
Card effect (current official text)Once per turn: You can Tribute 1 other monster; this card gains 1000 ATK until the End Phase. If this card attacks, change it to Defense Position at the end of the Battle Phase. One time only, when you draw a Monster Card during your Draw Phase while this card is in your Graveyard: You can reveal it; Special Summon it. This card must be in the Graveyard to activate and to resolve this effect.
Rulings
(1) Once per turn, by Tributing 1 monster, this card gains 1000 ATK until the end of this turn. (2) If this card attacks, it is changed to Defense Position at the end of the Battle Phase. (3) While this card is in the GY, one time only, when you draw a Monster Card during your Draw Phase you can show it to your opponent and Special Summon it.
- The (1) Ignition Effect Tributes 1 monster you control as cost.
- If Soul Exchange targeted your opponent's monster, you can Tribute it for this effect.
- You cannot Tribute more than 1 monster by this effect.
- Dasher CANNOT Tribute itself for this effect.
- The (2) Continuous Effect does not activate, it applies at the end of the Battle Phase.
- The (3) optional Trigger Effect follows a When... you can structure and can miss the timing.
- This effect starts a chain by revealing the drawn Monster Card.
- Dasher must be in the GY in order to activate this effect, but not to resolve it.
- If this effect / activation is negated, it CANNOT be used again until Dasher leaves the GY.
- If you draw 2+ monsters simultaneously (by Reload) while 2 copies of Dasher are in your GY: you may activate both in a chain.
- VS. Drastic Drop Off: Your turn player priority allows Dasher's effect to be Chain Link 1. However, your opponent can chain Drastic Drop Off to discard the Monster Card you drew.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the REDU forum — sourced change requests get reviewed.