Need some card hunt advice

Hello ,
This is Teara (Winnie) , Lv86 Crusader
Currently as of now I'm at 172 Monster Book Set (Tier 5)
I'll be Tier 6 in few hour after this post !
I've been consistently doing minimum 4 Set a day for 7days now (I did 10+ set sometime)

As i get closer to Tier 10 , its going to get harder so

I need advice on
Which card is very difficult that I should skip or really prepare my mental

I've done Reindeer,Cloud fox,Chunin,Kunoichi,Black Goat,Wild Kargo
(Honestly i consider them doable..)

Generally i try to skip bosses since I hate camping them
Feel free to LMK any easy Boss card like Centipede that nobody camp

Thanks for reading , I'll continue to slash blast my way to Tier 10

 

I've obviously read some Card hunt Guide
I need people to specify which card is difficult and if possible how long did it take and your class

100% Skipping Ashigaru
Unsure about Rombot & King Blocktopus... How difficult we talking O_O

I've also completed Baby seal which some people says its difficult .

Bosses Outside PQ I Completed - C.Balrog & Giant Centipede
Tier 10 By Lv 120 is my Goal (Within 2-3Months)

 

I'm doing by region instead of chapter , also skipping those that i can't 2-3hit and return to them later on
Maybe we can do malaysia themepark together one day when i'm abit stronger , feel free to add me