I completely agree with the lack of Water Elements so here is
Armourse:
Pretty basic design and looking into editing it.
Not liking the spikes around the tail but a bit of feedback would be great!
Next edit.
Quick sketch of Fwoggie… Made me giggle.
And Horsea (Horse + Sea) or Aquastrian (Aqua + Equestrian)
Thinking of removing the hind legs and going all tail.
I’ve drawn a composite sketch of a Mantisword+Chopperbug fusion monster. I can add colors and remove sketch lines if it’s an intriguing enough idea. Excalibug.
I would say post a picture!
Angelic spin on Moji:
Mosis
Edit: Camera angle makes it look abit longer than it is but it’s quite compact 
This would be nice for a fusion with Angelon
Harpy (Mythology Version) However, due to the age range of this game I’m wondering if it’s too indecent but if it’s gives others ideas then great!
Yes they are feathers! Just with no detail… Oh and the Wing/Arms need feathering, but that’s too much freaking effort
Edit Finished-ish.
Harpt would be a good one, i got to know harpy from Yugioh lol
Haha I was a bit of a Geek when if came down to Myths and Legends. Especially in the Greek era 
such as the Siren further up.
Try to Draw something like an undine ( water spirit )
Way ahead of you
The only other versions of her are generally legged and she wouldn’t seem very Arkadian like then.
We need better earth arks most the good ones are walls we need better I Want SandMan :3
Pretty much of what I’m saying is we need more offensive earth arks that defensive arks
Rooknight turns other earth monsters offensive…its presence makes Mossgolem offensive…then there’s Jumby and Golgy which are great…and can become killers with Rooky…what else…yeah, that’s it. 
So I agree!
Maybe an earth-type Ninja? We have Ninjagale, Flamogun, and Snowja…but no earth ninja…makes me sad 
Don’t forget Vegitiger - that one is Earth and *very* offensive towards certain groups. I’d also like to give small mention to Georex for being an offensive terrosaurus.
Oh yeah. Even so, a handful of monsters isn’t enough 
And most of those aren’t even that great.
@ Chrisie I think Aquastrian would be better, there already is a pokemon called Horsea
Lava raptor and geo Rex fusion? Post a picture or comment
How about a fusion monster between e.g. Shadow kit and minoflare or mossling and deletoid so then they have a use if you didn’t get 5 or so to create the online mission monster
Sounds good but what about stats. Your kinda restricted because if they were really good every one wood get one and with all the new OMs coming out it would be a lot of hassle to create all those fusion arkidons.
The idea sounds good indeed but i think Those Will be overpowered