Dan Lewis — ruling 1

The affected artifacts retain their other types and abilities.

Dan Lewis — ruling 2

An Equipment that's also a creature can't be equipped to anything unless it has the reconfigure ability.

Dan Lewis — ruling 3

If an artifact affected by Dan Lewis later becomes a creature, Dan's effect no longer applies to it. That artifact will stop being an Equipment and become unattached from any creature it was attached to; it will remain on the battlefield. The same thing happens if Dan leaves the battlefield.

Dan Lewis — ruling 4

While Dan is on the battlefield, an Aura enchantment that somehow becomes an artifact in addition to its other types will also become an Equipment. Any of its abilities that refer to either "enchanted creature" or "equipped creature" refer to the creature it's currently attached to. It can be attached to other creatures using its equip ability. If you try to attach the Aura Equipment to a creature it can't legally be attached to, it remains where it is. If the creature it's attached to becomes an illegal permanent for it to enchant, the Aura Equipment will be put into its owner's graveyard as a state-based action.

Dan Lewis — ruling 5

The Doctor's companion ability allows you to have two commanders if one has the ability and the other is a legendary creature that is a Time Lord Doctor and has no other creature types. Creatures with the changeling ability, for example, can't be a second commander this way.

Dan Lewis — ruling 6

Although Doctor's companion is a new variant of the partner ability, the rules for partner have not otherwise changed. Notably, Time Lord Doctors and cards with Doctor's companion do not interact with cards which have another partner ability.

Dan Lewis — ruling 7

If your Commander deck has two commanders, you can include only cards whose own color identities are also found in your commanders' combined color identities.

Dan Lewis — ruling 8

Both commanders start in the command zone, and the remaining 98 cards (or 58 cards in a Commander Draft game) of your deck are shuffled to become your library.

Dan Lewis : règles, fonctionnement et interactions (MTG)

Dan Lewis is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Noncreature, non-Equipment artifacts you control are Equipment in addition to their other types and have "Equipped creature gets +1/+0" and equip . Doctor's companion (You can have two commanders if the other is the Doctor.)

How it works : Dan Lewis

Original English text — Wizards of the Coast / Scryfall

#1October 13, 2023· Wizards of the Coast
The affected artifacts retain their other types and abilities.
No other card is named in this ruling.
#2October 13, 2023· Wizards of the Coast
An Equipment that's also a creature can't be equipped to anything unless it has the reconfigure ability.
No other card is named in this ruling.
#3October 13, 2023· Wizards of the Coast
If an artifact affected by Dan Lewis later becomes a creature, Dan's effect no longer applies to it. That artifact will stop being an Equipment and become unattached from any creature it was attached to; it will remain on the battlefield. The same thing happens if Dan leaves the battlefield.
No other card is named in this ruling.
#4October 13, 2023· Wizards of the Coast
While Dan is on the battlefield, an Aura enchantment that somehow becomes an artifact in addition to its other types will also become an Equipment. Any of its abilities that refer to either "enchanted creature" or "equipped creature" refer to the creature it's currently attached to. It can be attached to other creatures using its equip ability. If you try to attach the Aura Equipment to a creature it can't legally be attached to, it remains where it is. If the creature it's attached to becomes an illegal permanent for it to enchant, the Aura Equipment will be put into its owner's graveyard as a state-based action.
No other card is named in this ruling.
#5October 13, 2023· Wizards of the Coast
The Doctor's companion ability allows you to have two commanders if one has the ability and the other is a legendary creature that is a Time Lord Doctor and has no other creature types. Creatures with the changeling ability, for example, can't be a second commander this way.
No other card is named in this ruling.
#6October 13, 2023· Wizards of the Coast
Although Doctor's companion is a new variant of the partner ability, the rules for partner have not otherwise changed. Notably, Time Lord Doctors and cards with Doctor's companion do not interact with cards which have another partner ability.
No other card is named in this ruling.
#7October 13, 2023· Wizards of the Coast
If your Commander deck has two commanders, you can include only cards whose own color identities are also found in your commanders' combined color identities.
No other card is named in this ruling.
#8October 13, 2023· Wizards of the Coast
Both commanders start in the command zone, and the remaining 98 cards (or 58 cards in a Commander Draft game) of your deck are shuffled to become your library.
No other card is named in this ruling.
#9October 13, 2023· Wizards of the Coast
Once the game begins, your two commanders are tracked separately. If you cast one, you won't have to pay an additional the first time you cast the other. A player loses the game after having been dealt 21 combat damage from any one of them, not from both of them combined.
No other card is named in this ruling.
#10October 13, 2023· Wizards of the Coast
If something refers to your commander while you have two commanders, it refers to one of them of your choice. If you are instructed to perform an action on your commander (e.g. put it from the command zone into your hand due to Command Beacon), you choose one of your commanders at the time the effect happens.
No other card is named in this ruling.
#11October 13, 2023· Wizards of the Coast
An effect that checks whether you control your commander is satisfied if you control one or both of your two commanders.
No other card is named in this ruling.