: Until end of turn, Thopters you control have base power and toughness X/X, where X is the number of cards in your hand.
, : 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.
Leonardo is a mono-blue artifact value engine: every turn you loot with the activated ability, and discarding an artifact card exiles it to produce a flying Thopter copy of it. Stockpile artifacts in hand, churn through your deck to find big payoffs, then flip on the anthem to turn your Thopter army into a lethal X/X squad sized by your hand. You play a draw-go control shell that builds inevitability through repeatable card filtering and token generation.
Repeatable card advantage and selection that smooths draws and fills the yard
Can 'steal' the printed effect of any artifact you discard via the Thopter copy (mana rocks, equipment, Wurmcoil-style bodies)
Builds a wide evasive flying army that the first ability turns into a one-turn kill
Mono-blue gives access to the best counterspells, card draw, and interaction in the format
Both abilities are mana-hungry; the loot costs every turn and the anthem costs
The payoff anthem only lasts until end of turn, so it's all-in and vulnerable to instant-speed removal
Heavily reliant on Leonardo himself — losing the commander stalls the whole engine
Needs a healthy hand size for the anthem, which fights against expending cards on interaction
Token-wide strategies fold to board wipes and Thopter copies are fragile 0/2 bodies otherwise
Legendary Creature — Human Artificer
: 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.