Draw two cards, then discard a card.

{1}{U}, Discard a card: Draw a card.

Counter target spell unless its controller pays {2}.

Cycling {2} ({2}, Discard this card: Draw a card.)

Defender (This creature can't attack.)

{3}: Mobile Fort gets +3/-1 until end of turn and can attack this turn as though it didn't have defender. Activate only once each turn.

Flying

Thopter Squadron enters the battlefield with three +1/+1 counters on it.

{1}, Remove a +1/+1 counter from Thopter Squadron: Create a 1/1 colorless Thopter artifact creature token with flying. Activate only as a sorcery.

{1}, Sacrifice another Thopter: Put a +1/+1 counter on Thopter Squadron. Activate only as a sorcery.

Echo {4} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)

Thran War Machine attacks each combat if able.

Trample

{3}: Urza's Engine gains banding until end of turn. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

{3}: Attacking creatures banded with Urza's Engine gain trample until end of turn.