Huh? You basically win against a solo in one round? Is your party made exclusively of DPS monsters from the Wizards Character Optimisation boards?
Depends on your ability to generate multiple attacks in a nova round, and other buffs the warlord hands out. You don't have to be built for DPR, just for efficiency. If people bust out encounter power, AP, encounter power, and maybe one other person uses a daily, it will happen, especially with more organized players who are willing to shuffle around initiative for a beneficial order.
[sblock=Example]
Consider a level 8 party, lets say Warlord, Fighter, Invoker, Ranger, Rogue (I just grabbed a selection of characters from our various parties to test, though I scratch built the warlord since we don't have a tac lord).
Warlord walks up to enemy and opens up with Lead the Attack giving everyone +6 bonus, and doing 20 damage. For the sake of argument, I'm going to assume no one will miss in this fight with that +6 and soon coming combat advantage. The warlord then uses Adaptive Strategem on the Ranger. Saves his AP.
Invoker goes next, drops Rain of blood on solo and warlord for 13 damage, and then uses AP for thunder of judgement, dealing 27 more (17 base, +5 for vulnerability, +5 for AP benefit from warlord). Target is now also dazed granting CA to everyone.
Ranger goes next, skips HQ, uses move, Claws of the Griffon, Off-Hand Strike, AP, Twin Strike, triggering half-orc racial somewhere in there. Between adaptive strategem, the vulnerability, and the warlord AP benefit, he does 136 damage (36+25+25+25+25).
Fighter doesn't have any fancy tricks. Uses basic attack, AP, basic attack, for 41 damage (18+23).
Rogue goes, throws a dagger with sly flourish to get her sneak attack in, dealing 26, moves into melee for a minor low slash dealing 17 more. Then action points for Compel the Craven dishing 22 more points, and giving the warlord, ranger, and fighter opportunity attacks. Respectively they do 20 (including power bonus from invoker's Rain of Blood), 25, and 18 damage.
That brings the total tally up to 365 damage in one round. A level 8 solo with 18 Con will have around (9*8+18)*4 = 360 hit points.
You can see even against a higher level solo, the damage will be fairly crippling. The solo is dazed, rattled, and marked by the fighter. And the warlord still has his bonus till the end of his next turn and an action point as well as the bonuses from the invoker, so there is more potential there.
You don't need charop DPR monsters for monster damage, just a few good select powers, and coordination. The at-will powers of the above characters are Warlord 1d8+6, Invoker 1dX+10, ranger 1d10+5/1d10+5, Fighter 1d8+9, Rogue 1d4+10. For 8th level, this is nothing crazy.
Unfortunately, a ranger is always most helpful in these situations where bonuses are being handed out like candy. So this sort of nova could be more challenging without a ranger.
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