GFZ: Knuckles the echidna
This one is rather obvious if you managed to get far enough in Sonic and knuckles. Since our favorite red echidna never had any main point in the storyline other than going alongside sonic in his adventure or just being an addition since his appearance in SRB1, its no surprise to see him as a miniboss.
THZ:
http://www.sonicgalaxy.net/img/sprites/gen/sonic3/fusion-mb-2.png
One of two "fusion miniboss" designs made by Cstyler. This one has a front-mounted flame cannon for roasting rodents, along with several electricity conduits to assist with hedgehog disposal. The electric conduits also work as a backup plan in case the flame cannon is somehow destroyed. It also has several spikes encased inside it's top Armour for protection. I chose this one for Techno Hill because of it's unique design, with fire and electricity and all.
DSZ: This is another good place to have knuckles as a mini-boss.
CEZ: Sir Lance-a-lot
This is an idea i came up with myself. The premise of the boss is the same as the Mega Titan from the amazing mirror, but with a few differences. One is the obvious fact that instead of attacking with just his fists, he uses the lances from the CBFS badniks as sharp projectiles! These tend to wind up being everywhere in the area-the old JTE boss room-causing a lot of chaos.
Oh, and just like the end boss from the VERY old castle eggman stage, he uses rotating spikes as defense, so you may need to grab lots and lots of rings!
ACZ: Crawla Honcho
If you need help designing ACZ2 and RVZ2, check out this wad:
https://www.youtube.com/watch?v=6YAJSuHiz9U
Now, from here, i have some crazy boss ideas. The first is a fight against the flying bomber from S3&K(sprite sheet by grim):
http://www.sonicgalaxy.net/img/sprites/gen/sonic3/flying-bomber.gif
The second is a battle with a fan-favorite fan character: Crawla Honcho! I'll let you use your imagination to decide how the crazy crawla hero is gonna fight(and if you can't somehow add him in use the egg walker from SADX instead).
RVZ:
http://www.sonicgalaxy.net/img/sprites/gen/sonic3/fusion-mb.png
The other "fusion mini-boss" designed by Cstyler. This one uses a ROCKET LAUNCHA and can fly using jet engines. It serves as the last boss before metal sonic and is fought in the sky as both it and the player were launched out of the volcano on a platform during an eruption. The mini-boss? An upgraded version of Dual Drill from sonic 3 as seen in Lava Reef Zone.
ERZ: Nothing needs to be changed to the mini-boss other than making it appear in the second act instead of the third one, but that's just me. However, i would like to see if we could have metal knuckles and the tails doll replace metal sonic when their respected doppelgangers appear instead of just sonic, because it makes more sense. This makes it possible for tails and knuckles to get more of a challenge when facing metal sonic.