Tengu format ruling
Majestic Mech - Ohka

Card effect (current official text)You can Normal Summon this card without Tributing. If you do, during the End Phase: Send it to the Graveyard.
Rulings
- Flipping "Majestic Mech – Ohka" or "Majestic Mech – Goryu" face-down will not reset their memory of how they were Summoned. So if you Normal Summoned them with fewer Tributes by using their effect, they will still be sent to the GY by their effect during the End Phase even if they have been flipped face-down since being Summoned. (However, as long as they are face-down DURING the End Phase, their effect will not activate during that End Phase.)
- The effect of "Majestic Mech – Ohka" and "Majestic Mech – Goryu" that sends itself to the GY will activate during the End Phase of every turn (if they were Normal Summoned with fewer Tributes by using their effect).
- If "Skill Drain" is active during the End Phase, it will negate the effects of a "Majestic Mech" so the "Majestic Mech" will not send itself to the GY.
- If you activate "Cost Down" and Normal Summon "Majestic Mech – Ohka" without Tributes (because it is Level 4) or "Majestic Mech – Goryu" with 1 Tribute (because it is Level 6), their effects will still activate during the End Phase and they will be sent to the GY.
- The effect of a "Majestic Mech" to send itself to the GY is a Trigger Effect that can be chained to.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Tengu forum — sourced change requests get reviewed.