Minthara, Merciless Soul

Minthara has ward {X}, where X is the number of experience counters you have.
At the beginning of your end step, if a permanent you controlled left the battlefield this turn, you get an experience counter.
Creatures you control get +1/+0 for each experience counter you have.

Desynchronization

Return each nonland permanent that's not historic to its owner's hand. (Artifacts, legendaries, and Sagas are historic.)

Loyal Inventor

Vigilance
When this creature enters, you may search your library for an artifact card, reveal it, then shuffle. Put that card into your hand if you control an Assassin. Otherwise, put that card on top of your library.

Crystal Skull, Isu Spyglass

You may look at the top card of your library any time.
You may play historic lands and cast historic spells from the top of your library. (Artifacts, legendaries, and Sagas are historic.)
{T}: Add {U}.

Leonardo da Vinci

{3}{U}{U}: Until end of turn, Thopters you control have base power and toughness X/X, where X is the number of cards in your hand.
{2}{U}, {T}: Draw a card, then discard a card. If the discarded card was an artifact card, exile it from your graveyard. If you do, create a token that's a copy of it, except it's a 0/2 Thopter artifact creature with flying in addition to its other types.