Rory Williams

Partner with Amy Pond
First strike, lifelink
The Last Centurion — When you cast this spell from anywhere other than exile, exile it with three time counters on it. It gains suspend. Then investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Doctor Who

"Partner with [name]" represents two abilities. The first is a triggered ability: "When this permanent enters the battlefield, target player may search their library for a card named [name], reveal it, put it into their hand, then shuffle."

For example, if you cast Rory Williams from your hand, the triggered ability will exile it and it will gain suspend. When you cast it from exile, it resolves normally.

If you somehow counter the ability that triggers when you cast Rory Williams, it will resolve normally and will not be exiled.

Note that the target player searches their library (which may be affected by effects such as that of Stranglehold) and that the card they find is revealed, even though these words aren't included in the ability's reminder text.

Rory will resolve normally if cast from exile for any reason, not only if it was cast with its suspend ability.

The second ability represented by the "partner with [name]" keyword modifies the rules for deck construction in the Commander variant and has no function outside of that variant. If a legendary creature card with "partner with [name]" is designated as your commander, the named legendary creature card can also be designated as your commander.

Cards exiled with suspend are exiled face up.

Due to a recent rules change to suspend, you are no longer required to cast the suspended card as the second triggered ability of suspend resolves. Instead, as the second triggered ability resolves, you may cast the card. Timing permissions based on the card's type are ignored. If you don't cast the card, it remains exiled with no time counters on it, and it's no longer suspended.

Exiling a card with suspend isn't casting that card. This action doesn't use the stack and can't be responded to.

If an effect refers to a "suspended card," that means a card that (1) has suspend, (2) is in exile, and (3) has one or more time counters on it.

If the card has {X} in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.

If the first triggered ability of suspend (the one that removes time counters) is countered, no time counter is removed. The ability will trigger again at the beginning of the card's owner's next upkeep.

If the second triggered ability is countered, the card can't be cast. It remains exiled with no time counters on it, and it's no longer suspended.

If the spell requires any targets, those targets are chosen when the spell is finally cast, not when it's exiled.

If you cast a card "without paying its mana cost," such as with suspend, you can't choose to cast it for any alternative costs. You can, however, pay additional costs. If the card has any mandatory additional costs, you must pay those if you want to cast the card.

Suspend is a keyword that represents three abilities. The first is a static ability that allows you to exile the card from your hand with the specified number of time counters (the number before the dash) on it by paying its suspend cost (listed after the dash). The second is a triggered ability that removes a time counter from the suspended card at the beginning of each of your upkeeps. The third is a triggered ability that gives you the option to cast the card when the last time counter is removed.

The mana value of a spell cast without paying its mana cost is determined by its mana cost, even though that cost wasn't paid.

When the last time counter is removed, the second triggered ability of suspend (the one that lets you cast the card) triggers. It doesn't matter why the last time counter was removed or what effect removed it.

You can exile a card in your hand using suspend any time you could cast that card. Consider its card type, any effects that modify when you could cast it (such as flash) and any other effects that stop you from casting it (such as from Meddling Mage's ability) to determine if and when you can do this. Whether you could actually complete all steps in casting the card is irrelevant. For example, you can exile a card with suspend that has no mana cost or that requires a target even if no legal targets are available at that time.