What are excavated/relic weapons

Basically, the general strategy with the charge blade is to never convert energy into phials when it's glowing yellow, only red so you get the most out of each recharge. The gauge will gradually go from no glow to yellow to red as you attack in sword and shield mode. Once that hits red, hold R and press A to convert those into phials. Once you have those, the A attacks in axe mode get a serious boost to both KO ad damage, at the cost of one phial per attack. You generally want to go all out whenever you have three or more phials, and try to recharge in sword mode until you're back up to five. Also, if you realize you're going to miss with the axe mode A charge attack, press R to change the attack into a boost for your shield. That will make your shield as strong as a lance's for as long as the buff is active. Normal attacks in axe mode without phials are very wimpy compared to how much you could be dealing.

tl;dr Charge in Sword mode until red, recharge and mash A in Axe mode until phials are low, rinse and repeat.

Frenzy Virus

Description:

The Hunter becomes infected with a virus. It requires time to incubate, represented by a purple bar filling up below the Hunter's on-screen name. If the bar fills completely, the virus negates natural health recovery, meaning that the Hunter takes full damage from attacks without being able to heal back half of it. Additionally, all attacks which would cause the condition will deal extra damage while the virus is active. However, if the Hunter inflicts enough damage on a monster whilst the virus is incubating, they gain a 15% Affinity boost instead, as well as an immunity to infection for a short period of time.

Remedy:

While incubating, the incubation can be delayed by consuming a Nulberry. The fully incubated virus can only be cured by prolonged exposure to a Panacea or waiting it out.

source

I can confirm this information is correct. The Gore Magala and Shagaru Magala are the primary monsters that deal this status effect. Additionally, infected monsters (ie. Infected Tigrex) will gain the ability to deal this status effect.

If the virus fully incubates and you get the debuff, it's easier to simply run to another area. The debuff should go away after a minute. Attempting to fight the monster with the incubated virus is a death wish, as many attacks do extra damage. A recent fight against Shagaru Magala showed me just how many attacks can one-shot me under this debuff.