Doran, Besieged by Time - Intelligence

Doran is commander/deckbuilding intelligence, not confirmed market movement. Check toughness-heavy creatures, defender permission, Treefolk overlap, trample conversion, exact ECL printings, CardTrader supply, TCGplayer pricing, and Pricing Confidence before trusting a move.

Doran's first ability is static. It applies only to creature spells its controller casts with toughness greater than power, reduces only generic mana by {1}, and does not change mana value.

The reduction is part of total-cost calculation and is applied after cost increases and other reductions are considered.

The second ability triggers separately for each creature its controller controls that attacks or blocks. The ability does not target.

X is calculated once as each trigger resolves using the absolute difference between the creature's current power and toughness. A 3/5 and a 5/3 both produce X equal to 2; equal stats produce X equal to 0.

Power or toughness changes before the trigger resolves affect X. Changes after resolution do not recalculate the existing +X/+X bonus.

The creature gets both +X power and +X toughness until end of turn.

Doran, Besieged by Time does not make creatures assign combat damage using toughness. Doran, the Siege Tower and cards like Assault Formation are separate redundant engines with different rules text.

Doran does not remove defender. Defenders can trigger Doran while blocking, but they need another effect to attack.

Triggers already on the stack survive Doran leaving the battlefield. First strike and double strike do not create extra Doran attack or block triggers.

Multiple Doran triggers are cumulative and calculate independently. Continuous effects still use normal layer rules.

Curve high-toughness creatures into Doran, then attack with bodies whose power and toughness are far apart.

Use Treefolk tutors, cost reducers, lords, and naturally high-toughness creatures as the Doran creature base.

Use cheap defenders for ramp, cards, and high toughness, then add separate effects that let them attack.

Use Doran's block trigger to make large-toughness blockers trade up, then convert stabilized boards into attacks.

Use high-toughness lifegain creatures and life-total exchange cards as a slower resilience package.