Dralnu, Lich Lord

To determine the total cost of a spell, start with the mana cost or alternative cost (such as a flashback cost) you're paying, add any cost increases, then apply any cost reductions. The mana value of the spell is determined only by its mana cost, no matter what the total cost to cast the spell was.

Dralnu may be one of the permanents you sacrifice while applying its replacement effect.

If a card with flashback is put into your graveyard during your turn, you can cast it if it's legal to do so before any other player can take any actions.

If a card has multiple instances of flashback, you may choose any of its flashback costs to pay.

A spell cast using flashback will always be exiled afterward, whether it resolves, is countered, or leaves the stack in some other way.

If a split card gains flashback, you pay only the cost of the half you're casting.

If you cast an instant or sorcery with {X} in its mana cost this way, you still choose the value of X as part of casting the spell and pay that cost.

If any of the sacrificed permanents would deal or be dealt damage at the same time as Dralnu, they deal or are dealt damage at the same time that they're sacrificed. Any abilities of the sacrificed permanents that would trigger on that damage don't trigger, but abilities of other permanents that trigger on that damage do.

If you cast a spell with flashback, you can't pay any alternative costs such as overload costs. You can pay additional costs such as kicker costs. If the spell has any mandatory additional costs, you must pay those to cast the spell with flashback.

If Dralnu would be dealt more damage than the number of permanents you control, instead you sacrifice all permanents you control.