Demons you control have
menaceMenace is an evasion ability.
A creature with menace can’t be blocked except by two or more creatures. (See rule 509, “Declare Blockers Step.”)
Multiple instances of menace on the same creature are redundant. (CR 702.111),
lifelinkLifelink is a static ability.
Damage dealt by a source with lifelink causes that source’s controller, or its owner if it has no controller, to gain that much life (in addition to any other results that damage causes). See rule 120.3.
If an object is no longer in the zone it’s expected to be in as an effect causes it to deal damage, its last known information is used to determine whether it had lifelink.
The lifelink rules function no matter what zone an object with lifelink deals damage from.
If multiple sources with lifelink deal damage at the same time, they cause separate life gain events (see rules 119.9–10).
Multiple instances of lifelink on the same object are redundant. (CR 702.15), and
hasteHaste is a static ability.
If a creature has haste, it can attack even if it hasn’t been controlled by its controller continuously since their most recent turn began. (See rule 302.6.)
If a creature has haste, its controller can activate its activated abilities whose cost includes the tap symbol or the untap symbol even if that creature hasn’t been controlled by that player continuously since their most recent turn began. (See rule 302.6.)
Multiple instances of haste on the same creature are redundant. (CR 702.10).
Starscourge — At the beginning of combat on your turn,
exileTo exile an object, move it to the exile zone from wherever it is. See rule 406, “Exile.” (CR 701.13) up to one target creature card from a graveyard. If you exiled a card this way,
createTo create one or more tokens with certain characteristics, put the specified number of tokens with the specified characteristics onto the battlefield.
If a replacement effect applies to a token being created, that effect applies before considering any continuous effects that will modify the characteristics of that token. If a replacement effect applies to a token entering the battlefield, that effect applies after considering any continuous effects that will modify the characteristics of that token.
Previously, an effect that created tokens instructed a player to “put [those tokens] onto the battlefield.” Cards that were printed with that text have received errata in the Oracle card reference so they now “create” those tokens. (CR 701.7) a token that's a copy of that card, except it's a 5/5 black Demon.