Fixes#1690. Addresses Blood Oath holistically — three bugs found while researching the spell against RunUO, ServUO, the UODemise/uo.com guides, and the archived UOGuide page.
## Bugs fixed
### 1. Expiry timing (the filed issue)
The `ExpireTimer` polled every 1s, so expiry and death/delete cleanup lagged up to ~1s. Replaced with a **single-shot** timer plus centralized `[OnEvent]` handlers on `PlayerDeathEvent`/`PlayerDeletedEvent`/`CreatureDeathEvent`/`CreatureDeletedEvent` — the oath now breaks immediately on death/delete of either party.
### 2. Duration formula
Used `/80` (the bugged in-game tooltip value) instead of the real OSI formula `((SpiritSpeak - Resist) / 8) + 8`. Confirmed by RunUO, ServUO, the emulator guides, and the code's own fixed-point comment. At GM Spirit Speak this changes duration from ~9.5s to 23s and makes Spirit Speak actually affect duration.
### 3. Damage reflection (`BaseCreature.Damage` vs `PlayerMobile.Damage`)
`BaseCreature.Damage` diverged: it attributed the reflected hit to the attacker itself (`from.Damage(amount, from)`) instead of the caster, reflected the bonused (not original) amount, used `×1.1` vs `×1.2`, lacked the caster-survival guard, and had no Publish 48 resist mitigation.
Unified both paths: reflect the **original** damage attributed to the **caster** at `×1.2`. Publish 48 resist mitigation now applies only to creature casters and is gated behind `Core.SA`.
## Internals
- Collapsed the parallel `_oathTable` into a single `_table` keyed by both participants → shared timer, so `RemoveCurse` resolves from either side (required by the event handlers).
- Extracted `GetDurationSeconds` and `ComputeReflectedDamage` as testable statics.
## Tests
13 new tests (duration formula, reflection mitigation, oath lifecycle, end-to-end event-driven removal). Full suite: **436/436 pass**.
## Issue
Fixes#2452. A player with 30 Ninjitsu reported that the Animal Form menu showed **every** form; selecting one above their skill (e.g. Dog, req 40) **consumed mana** and returned "you need at least 40 skill", and afterwards the **gump never reopened** — every recast silently re-attempted the unusable form and drained more mana.
## Root cause
Three linked bugs, all reproduced from the code:
1. **Gump not gated by skill.** `AnimalFormGump.BuildLayout` compared `Skill.Fixed` (which is `Value * 10`, so 30 skill → `300`) against the raw 0–100 `ReqSkill` (Dog = `40`). `300 >= 40` is always true, so all forms were shown. `Morph` itself correctly uses `.Value`.
2. **Mana charged on a no-skill cast.** `Morph` returns `MorphResult.NoSkill` for an under-skilled form, but both call sites (`OnCast`, `OnResponse`) only special-cased `MorphResult.Fail`; `NoSkill` fell through to the branch that deducts mana.
3. **Menu never reopened.** Per OSI ([uo.com](https://uo.com/wiki/ultima-online-wiki/skills/ninjitsu/), [uoguide](https://www.uoguide.com/Animal_Form)), casting while **standing still always opens the selection menu**, and casting while **moving** quick-transforms into the last selected form. ModernUO only opened the menu when `lastAnimalForm == -1`, so once any form was selected a stationary recast skipped the menu.
## Fix
- Add `AnimalForm.CanSelectEntry` (compares `Skill.Value` to `ReqSkill`, plus the talisman check) and use it for the gump's per-entry enable check.
- `OnCast`: standing still always opens the menu; moving quick-transforms into the last form. `NoSkill` no longer costs mana.
- `OnResponse`: handle `Success` / `Fail` / `NoSkill` explicitly so `NoSkill` costs no mana.
## Tests
Adds `AnimalFormTests`:
- `CanSelectEntry` rejects forms above skill, accepts forms at/below skill, and requires a talisman for talisman-gated forms.
- `Morph` returns `NoSkill` (without transforming) when under-skilled, and `Success` when sufficiently skilled.
Verified the gating test catches the regression (reintroducing `.Fixed` fails it). Full solution build is clean; the 5 new tests plus 284 other UOContent tests pass (the pathfinding/AI sequential tests were excluded only because they deadlock under concurrent local runs — they are unrelated to this change).
