New RPG-influenced Chess Variant as a Telegram Bot

To start a new game with yourself, send the /newgame command to the @chess_upgraded_bot bot. The /newturbo command will start a turbo game where all pawns have 10 experience at once. The /newelite command will start a game where the rooks and the knights have already been upgraded.

To play with another person, add the bot to the chat and enter the moves one by one.

Moves are accepted in short algebraic notation. Don't specify the checks, checkmates and captures. Type all moves in a simple way, for example nge2. Castling is 0-0. Pawn promotion goes with the desired piece at the end: g8q.

Upgrades

When capturing enemy pieces, bishops, knights, rooks and pawns gain experience.

Queen — 10 exp,
Rook  — 7,
Bishop — 5,
Knight  — 5,
Pawn — 2,
Own pawn — 1.

When a piece with some exp is captured, all of its exp goes to the capturing piece. When an own pawn is captured, its gained exp burns out.

A rook, bishop, and knight, get the 2nd level when they gain 10 exp.

An upgraded rook additionally receives moves of the knight.
An upgraded bishop spawns a second bishop binded nearby. Bishops move together, they can capture two pieces at once, and both disappear if the opponent captures one.
An upgraded knight additionally jumps diagonally over one square in all directions.

A pawn, promoting to a piece, keeps its experience. Pawn cannot be promoted to the bishop.

Besides that, standard chess rules apply.