Takenuma, Abandoned Mire

Suit Up will overwrite any previous effects that set the creature or Vehicle's power and toughness to specific numbers. Effects that otherwise modify its power and toughness will still apply no matter when they took effect. The same is true for +1/+1 counters.

If Suit Up causes a Vehicle to become an artifact creature, it doesn't count as “crewing” that Vehicle for any ability that would trigger off of a Vehicle becoming crewed.

The creature or planeswalker card you return to your hand is not chosen until after you mill three cards. You may choose a creature or planeswalker card from among all the cards in your graveyard, including the milled cards.

Discarding the card is part of the cost to activate a channel ability.

If a channel ability requires a target, you may not activate it without a target just to discard the card.