Doomsday/Blackest Night

Doomsday Blackest Night is the ultimate destructive monster. He can only be obtained by ranking in the top 5% or higher in Online Battle seasons.

Strategy
The power of his specials will further increase every 7 seconds he remains in play from either the start of the match (if he's the first character) or upon him tagging in. This boost can stack up to 3 times and remains upon use of a special. The counter to gain the first or each additional boost will reset upon tag-out, but any boost he has acquired will remain for the entire match.

As his added power is dependent upon remaining in play, gear focused on increasing his longevity is a good idea. The full Fourth World Set can give him a powerful regen effect on s1 and has effects that increase his total health, along with the effectiveness of blocking, in addition to a chance of other odd defensive benefits occurring due to its various effects. Alternatively, the LexCorp Set 2-piece effect can reverse the effect of power drain, which can otherwise render Doomsday's passive ineffectual even if he remains in play. While not boosting health in the same way, the set does offer its own effects that bolster blocking, and two individual pieces both offer different ways to restore health.

Riddler's Staff offers a health increase and a chance to evade incoming s1 attacks. His own gear, Bone Spikes/Mutated Bone Spikes, offers a heal on s1.

Interactions
Good with
 * Lex Luthor/Krypto : his passive offers a 30% maximum health boost to all members of the team, and Doomsday has the tied-highest base health in the game and favors effects that bolster him without removing him from play.
 * Any character that increases power generation : Doomsday's passive is tied to his special attacks, so faster power generation means his passive has a better effect.

Good against

Countered by
 * Sinestro/Antimatter : his passive will tag Doomsday out and drain his power, nullifying his passive. But as noted above, if Doomsday reaches his first boosts, it will remain there during the whole match, regardless of tagging out or not. Thus, the best way to counter him is to tags him out before he's in play for 7 seconds.
 * Hawkgirl/Regime : Her passive will disable his specials for 5 seconds upon tag in.
 * Darkseid/Apokolips : he has a high chance of putting one or two effects (Bleed and Crit) on Doomsday upon using his combo ender that can severely limit Doomsday's health and cannot be removed without switching out, resetting his passive (unless he reaches the first boost).
 * Any character that can drain power : Doomsday's play style favours him staying in the field, but tagging out is often the best defence against power-draining characters. This means that, even if Doomsday reaches full boost, he will not have much power that can utilise this boost.
 * Killer Frost: Doomsday cannot use special attacks as frequently due to Killer Frost's power nullification passive.

Abilities
Here are Doomsday's abilities.

Trivia

 * Despite being an online challenge character, his promotions are "Available In Booster Packs". It is unknown if this in an error or foreshadowing a future pack.
 * Even though he is a Doomsday character, he did not register as such for the requirement of the repeat of the Superman/Godfall challenge held right after Blackest Night Doomsday's first online season ended. This was fixed in the Superman/Injustice 2's Challenge.
 * He's the second character to have his special be perfomed "outside" of the traditional left-to-right special (his SP2 showcased the perspective from above the player's POV). The first being Darkseid/Apokolips and follow-up is Superman/Injustice 2.