There are about hundreds of characters in the game. The best thing is, the game is keep updating. In this October Halloween season, the game simply put characters in Halloween theme and we'll able to summons them. As illustrated in this video :
Meanwhile here are the screenshot maps for Tales of Link quests. Each map / area has several quests and each quest will have several rounds to clear off.
Nialith Borderland (Difficulty *) :
- Forest of Narnica
- Placid Riverside
- Robhal Pass
- Zola Forest
- Wayfarers' Town
- Zola Forest - Otherworld
Mt. Harnica Area (Difficulty **):
- Mt. Harnica Road
- Sawtooth Road
- Phatos' Shortcut
- Bandits' Den
- Hope Bridge - Base
- Hope Bridge - Gaping Mount
Deijil Region (Difficulty ***) :
- Ryuka's Fight
- Dona Plateau
- Rainy Forest Path
- Riede Forest - Pursuit
- Kamsur Prairie
- Wolf of Ruin
Roard Region (Difficulty ****) :
- Liada Roadway
- Neverbreeze Woodlands
- Hojiroshi Roadway
- Ios Village
- Corina Mountain Road
- Bewitching Thicket
- Blightland of Lanastary
Storm-Shadowed Sairan (Difficulty ******) :
- Sairan Alliance Capital
- Forest of Cages
- Phlotta Roadway
- Gleaning Grove
- Road Back to Capital
- Lydore Ruins
- Swyra Backroad
Sairan Vortex of Schemes (Difficulty ******) :
- To Sairan Capital
- To Elaym
- Back Alley Battle
- Toreia Riverside
- Scahra Woods - Interior
- Cavern Interior / Hideout
- Shadowy Cavern
Sairan Battleground :
- Gates of Sairan
- Main Street
- Southern Business Ward
- Administrative Ward
- Western Park
- Western Marketplace
- Northern Cathedral
Otherworld Goddess :
- Blazewoods of Rupart