I am building a Nakudama Monk with the Nakudama's Electric Bloodline feat and it says in the feat description "You have an electrified tongue that you can use to make unarmed strikes. It has the finesse and reach properties, and when you hit with it, the strike deals lightning damage equal to 1d6 + your Strength or Dexterity modifier, instead of the bludgeoning damage normal for an unarmed strike. The damage from your tongue increases when you reach 5th level (1d8), 11th level (1d10), and 17th level (1d12)." Now this may seem like a dumb question, but I was wondering if I could get some kind of clarification for this, would I be able to use the tongue attack in place of my flurry of blows when rolling for it since it says in the Flurry of Blows description that I make 2-3 unarmed strikes depending on the level, and the tongue attack counts as an unarmed strike.

Another question, or I guess request, is can I get some suggestions for what feats I should take for this character since I am trying to focus on using the tongue attack pretty frequently if it actually does work with the flurry of blows bonus action. I am planning on having him either be Warrior of the Elements, Warrior of the Open Hand, or Warrior of the Street.

I don't see any reason why you wouldn't be able to use that for Flurry of Blows. Flurry of Blows involves making unarmed strikes and it specifically says you can use the tongue to make unarmed strikes. The damage progression given is the same as the 2024 Monk's unarmed damage progression, so it's really just changing the damage type and adding extra reach.

It's worth noting that these benefits will be somewhat superseded by the main feature of Warrior of the Elements if you go that route, since it also increases the reach of unarmed strikes (by more) and changes the damage type (to one of several choices including lightning). That's not to say you shouldn't do it, it's just that the electric tongue thing is not getting you much that way.

If the rule says you can make unarmed strikes with it, then you can - be sure to be aware of how many times per turn or day are on that ability, some class features have limits, others don't.

@wagnarokkr Yeah I was thinking that too. I think Im going to stick with the Warrior of the Streets since we are doing a Gladiator arena style game and we will be doing a homebrew rule that the armor, weapons, and shields can be destroyed like objects (reason being is that since we're gladiators we are given really low quality gear), so the Iron Fist class ability from the Warrior of the Streets will be great for that. Also every victory gives a level.

I'm not familiar with Warrior of the Streets (a third party subclass?) but that does sound like a good choice in that particular environment.

Quote from wagnarokkr >>

I'm not familiar with Warrior of the Streets (a third party subclass?) but that does sound like a good choice in that particular environment.

 It's from Valda's Spire of Secrets.