Set bonuses & artifacts

Bonuses for having certain units on the board together, and what the artifact does - from the older list.

Set bonuses

Have all the units in a row on the board at the same time to get the bonus.

On the board	Bonus
Stettman + Tychus + Commando Raynor	+60% damage for “Raynor & guys”
K5 + Commando Raynor	+40% damage for all bio
Voidray + Void Seeker + Hyperion + F-Archangel	+50% for all mech (and some Protoss)
Tosh + Laser + Tempest + Spore Cannon	+50% damage for all buildings
Mothership + Tychus + K5 Kerrigan + Gorgon	+50% damage for all units
Vile Roach + Queen + Dominion Marauder + Warp Prism	Enemy speed reduced by 15%
Artifact	+10% movement speed
Selendis + Gorgon	+100% interceptor damage, for both units
Mohandar + Selendis	+30% damage for all Protoss
4× Nova	25% faster cooldown
4× Raven	25% faster cooldown
8× Odin	+100% Odin damage (spells too)
100× units in total	+20% damage for all units

Artifacts

The older list names five things an artifact can do:

1. Random unit from the $1 lottery
2. Random unit from the $3 lottery
3. Random unit from the $5 lottery
4. Create a hidden combo (not hardcore units)
5. Create a hell combo

Its author also describes the newer artifact:

• It is weak until about round 50 to 55. After that it is probably the highest-damage weapon in the game: each pulse leaves a burn that lasts until the next one, so the many units on the board stop regenerating, which is the hardest part of the game.
• It can be upgraded, and its rank can be reset.
• Around round 70 to 75 regeneration outpaced it. The author stopped upgrading at level 4, having run out of saves, and still reached round 92. Going further probably needs the upgrades maxed.