Terra (Boss)

Description
Terra is a boss focused around tiles, reducing the area the player can use to dodge. Most of her attacks also feature spinners that turn counterclockwise when hitting a broken tile or the edge of the player's half of the field.

When spared, Terra will occasionally appear at the start of battle and 6 unoccupied enemy tiles at random.

Strategy
Spinner movement can be hard to predict on the fly, so having a plan for each attack pattern is particularly helpful against Terra. Spells which break tiles on your own side of the field can be risky if used at the wrong moment. A player can occupy a tile Terra is about to break without being forced to move, but they will take 80 damage and the tile will be.

Because of Terra's reliance on breaking tiles, spells and artifacts which involve broken tiles are especially helpful against her:
 * allows the player to fly over broken tiles, making many of her attacks trivial to dodge.
 * grants the player 10 shields every time a tile is broken, while grants 0.2  for each currently cracked or broken tile; both of these effects can quickly add up during the fight.
 * fires a shot from each broken tile which targets Terra, making it handy for some extra damage, while grants 10 shields for each broken tile in addition to fixing all of them, making Terra's current attack easier to deal with.
 * While normally cracks adjacent tiles, on  it instead fixes them, including tiles already broken by Terra, making it potentially useful in a pinch.

While Terra doesn't move very much while she's attacking, between attacks she repeatedly teleports in her grid, and because the player likely won't be in the same row as her while dodging her attacks, spells which apply are still helpful against her. In addition, because of said teleporting, is particularly effective against her: If used between her attacks, she'll likely hit almost every mine and take large amounts of damage.

"Corner" as used below refers to one of the four corners of the player's half of the field. All spinners do 20 damage each time the player touches one.

Expanded Corner Break with Line Strikes

 * Breaks the corner tiles and attacks lines to force the player to move.
 * Additional column, horizontal, or diagonal lines can be attacked at tier 3+.

Line Break(s) with Spinners

 * Spawns two spinners and breaks one row, one column, or both a row and column after a short delay. Getting trapped with a spinner in a single row/column can result in a large amount of damage.
 * Additional column, horizontal, or diagonal lines can be attacked at tier 3+.

Corner Break with Spinners

 * Spawns two spinners, breaking two opposite corners and the tiles immediately above/below them after a short delay. The tiles are positioned such that each spinner will be confined to one half of the player's side of the field, though the player is not blocked from moving between the two halves.
 * Additional column, horizontal, or diagonal lines can be attacked at tier 3+.

Center Break with Spinners

 * Spawns two spinners and breaks the four center tiles, forcing the player to move counterclockwise along with the spinners to avoid being hit.
 * Additional column, horizontal, or diagonal lines can be attacked at tier 3+.

Targeted Breaks with Spinners

 * Spawns two spinners and fires a sequence of five (60-damage?) shots that each aim to break the tile the player is standing on. Moving in a counter-clockwise direction between shots or staying in the center tiles when possible will help avoid the spinners.

Targeted Spinners

 * Spawns a sequence of ten spinners, each targeting the tile the player is standing on and landing after a short delay. Each spinner moves to the left after landing. No tiles are broken, so spinners will accumulate around the outer tiles of the player's half of the field.

Targeted Breaks

 * Fires a sequence of ten 60-damage shots that each aim to break the tile the player is standing on. The player must avoid being trapped in place before the last shot is fired.

Corner Break with Diags

 * Breaks the four corners. A diamond appears and moves diagonally between tiles, tracing a counterclockwise 'circle' that ends where the diamond was first spawned. It does 40 damage each time the player touches it, which severely punishes frantic movement. At tier 3+, another diamond may appear on an adjacent tile and trace a similar path, the attack may be repeated multiple times in a row, and one or both tiles may contain multiple stacked diamonds that each hit the player separately.