who is more dangerous than Dajjal for Shia?

بسم الله الواحد القهار

Sheikh Hurr Al-Ameli:

It has been narrated in Sifaat Ash-Shi'a (of Sheikh As-Saduq) from Mohammad Ibn Musa Ibn Al-Mutawakkil from Mohammad Ibn Yahya from Ahmed Ibn Mohammad from Al-Hasan Ibn Ali Al-Khazzaz who said I heard Imam Ar-Ridha (عليه السلام) saying : Some of those who claim the love for us, the Prophet's household, are more dangerous for our Shia than the ordeal of the Dajjal. 
I asked: How are they more dangerous? The Imam (عليه السلام) answered : They support our enemies and antagonize our followers. When this occurs , the Truth will be confused with the Falsehood and the whole matter will be perplexed. Then the Believers can't be distinguished from the Hypocrites.

Source: Wasael Ash-Shia, Vol. 16 Pg.  179

Attestation of the chain:

This narration is authentic and all of its narrators are trustworthy(Thiqa).
The narrators can be found in the Rijaal section. Look up the narrators with the corresponding numbers.

1794: Mohammad Ibn Musa Ibn Al-Mutawakkil
1819, 1820: Mohammad Ibn Yahya
130: Ahmad Ibn Mohammad
501: Al-Hasan Ibn Ali Al-Khazzaz