Welcome back! There’ve been a lot of fun things added in the past year, like Raid Tournaments.
I like your 4* roster. I’d build that up a bit more before working on any 5* (particularly because none of the ones you have are really exciting). I’d focus on:
Purple - Tibertus, then Rigard. Although you have two of the Ramming Pulverizer trio, Tibby is very useful particularly because yellow tanks are so popular. Rigard is the best 4* healer in the game and the only 4* with a team-wide cleanse.
Yellow - Jackal is a superb hero; I’ve put emblems on him to +19 and regularly bring him to raids and wars paired with another yellow sniper (Joon for me, Chao for you). Once he’s done, i’d use yellow feeders on another project until you get a yellow 5* or Gretel.
Blue - finish Sonya then shift to Richard.
Green - Melendor then Horghall. You want Mel to build your healer roster up. You should have 6 healers minimum for alliance wars, one per team, especially facing the arrows. Horghall is not my choice of 5*, but he’s what you’ve got. Little John has his uses, but he’s very fragile.
Red - Wilbur is the priority here—put him and Wu on every titan, and you’ll be doing much better. Colen has his uses, but i’d probably move to Khagan after Wilbur.
I recommend training five heroes at a time at typur stage in development, one of each color. There’s a 20% experience bonus for feeding matched-color, which really helps build up your overall roster faster.
Hope that helps!